1.assets usually put pictures, css and so on, which will be processed by webpack. For example, some small images will be converted to base64, and a series of functions such as hash will be added to the file path, depending on how you configure
2. Files under the static directory will not be processed by webpack , you can access

directly through / static/xxx this depends on the directory structure and loading mode of the files you have packaged, as well as the configuration of your server, which is difficult to generalize. To put it simply, you can also do an alias in the server configuration.

remember: the resources in
assets are all packaged and compressed. The files placed in
static under the dist folder are directly copy to the dist folder, and will not be packaged and compressed.

the reference path of the static file before compression is the same as the path after compression (if you haven't tampered with the configuration file)

webpack.base.conf.js

'use strict'
const path = require('path')
const utils = require('./utils')
const config = require('../config')
const vueLoaderConfig = require('./vue-loader.conf')

function resolve (dir) {
    return path.join(__dirname, '..', dir)
}

// const createLintingRule = () => ({
//     test: /\.(js|vue)$/,
//     loader: 'eslint-loader',
//     enforce: 'pre',
//     include: [resolve('src'), resolve('test')],
//     options: {
//       formatter: require('eslint-friendly-formatter'),
//       emitWarning: !config.dev.showEslintErrorsInOverlay
//     }
// })

module.exports = {
    context: path.resolve(__dirname, '../'),
    entry: {
        app: './src/main.js'
    },
    output: {
        // webpack:/dist
        path: config.build.assetsRoot,
        // webpackbundlemd5Hashscript
        filename: '[name].js',
        // webpack()
        publicPath: process.env.NODE_ENV === 'production'
            ? config.build.assetsPublicPath
            : config.dev.assetsPublicPath
    },
    resolve: {
        // ,
        extensions: ['.js', '.vue', '.json'],
        alias: {
            'vue$': 'vue/dist/vue.esm.js',
            '@': resolve('src'),
        }
    },
    module: {
        rules: [
            // ...(config.dev.useEslint ? [createLintingRule()] : []),
            {
                test: /\.vue$/,
                loader: 'vue-loader',
                options: vueLoaderConfig
            },
            {
                test: /\.js$/,
                loader: 'babel-loader',
                include: [resolve('src'), resolve('test'), resolve('node_modules/webpack-dev-server/client')]
            },
            {
                test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
                loader: 'url-loader',
                // queryloader,query  options 
                options: {
                    limit: 10000,//10000base64
                    name: utils.assetsPath('img/[name].[hash:7].[ext]') //name.7hash.
                }
            },
            {
                test: /\.(mp4|webm|ogg|mp3|wav|flac|aac)(\?.*)?$/,
                loader: 'url-loader',
                options: {
                    limit: 10000,
                    name: utils.assetsPath('media/[name].[hash:7].[ext]')
                }
            },
            {
                test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
                loader: 'url-loader',
                options: {
                    limit: 10000,
                    name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
                }
            },
            {
                test: /\.less$/,
                loader: 'style-loader!css-loader!postcss-loader!less-loader'
            },
            {
                test: /\.pug$/,
                loader: 'pug'
            }
        ]
    },
    node: {
        // prevent webpack from injecting useless setImmediate polyfill because Vue
        // source contains it (although only uses it if it's native).
        setImmediate: false,
        // prevent webpack from injecting mocks to Node native modules
        // that does not make sense for the client
        dgram: 'empty',
        fs: 'empty',
        net: 'empty',
        tls: 'empty',
        child_process: 'empty'
    }
}

webpack.dev.conf.js

'use strict'
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const merge = require('webpack-merge')
const path = require('path')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin')
const portfinder = require('portfinder')

const HOST = process.env.HOST
const PORT = process.env.PORT && Number(process.env.PORT)

const devWebpackConfig = merge(baseWebpackConfig, {
    module: {
        //rulessourceMap: false,sourceMap
        rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap, usePostCSS: true })
    },
    // cheap-module-eval-source-map is faster for development
    devtool: config.dev.devtool,

    // these devServer options should be customized in /config/index.js
    devServer: {
        clientLogLevel: 'warning',
        historyApiFallback: {
            rewrites: [
                { from: /.*/, to: path.posix.join(config.dev.assetsPublicPath, 'index.html') },
            ],
        },
        hot: true,
        contentBase: false, // since we use CopyWebpackPlugin.
        compress: true,
        host: HOST || config.dev.host,
        port: PORT || config.dev.port,
        open: config.dev.autoOpenBrowser,
        overlay: config.dev.errorOverlay
            ? { warnings: false, errors: true }
            : false,
        publicPath: config.dev.assetsPublicPath,
        proxy: config.dev.proxyTable,
        quiet: true, // necessary for FriendlyErrorsPlugin
        watchOptions: {
            poll: config.dev.poll,
        }
    },
    plugins: [
        new webpack.DefinePlugin({
            'process.env': require('../config/dev.env')  //
        }),
        new webpack.HotModuleReplacementPlugin(),
        new webpack.NamedModulesPlugin(), // HMR shows correct file names in console on update.
        new webpack.NoEmitOnErrorsPlugin(),
        // https://github.com/ampedandwired/html-webpack-plugin
        new HtmlWebpackPlugin({
            filename: 'index.html',
            template: 'index.html',
            inject: true
        }),
        // copy custom static assets
        new CopyWebpackPlugin([
            {
                from: path.resolve(__dirname, '../static'),
                to: config.dev.assetsSubDirectory,
                ignore: ['.*']
            }
        ])
    ]
})

module.exports = new Promise((resolve, reject) => {
    portfinder.basePort = process.env.PORT || config.dev.port
    portfinder.getPort((err, port) => {
        if (err) {
            reject(err)
        } else {
            // publish the new Port, necessary for e2e tests
            process.env.PORT = port
            // add port to devServer config
            devWebpackConfig.devServer.port = port

            // Add FriendlyErrorsPlugin
            devWebpackConfig.plugins.push(new FriendlyErrorsPlugin({
                compilationSuccessInfo: {
                    messages: [`Your application is running here: http://${devWebpackConfig.devServer.host}:${port}`],
                },
                onErrors: config.dev.notifyOnErrors
                    ? utils.createNotifierCallback()
                    : undefined
            }))

            resolve(devWebpackConfig)
        }
    })
})

webpack.prod.conf.js

'use strict'
const path = require('path')
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const merge = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const ExtractTextPlugin = require('extract-text-webpack-plugin')
const OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
// 
const ImageminPlugin = require('imagemin-webpack-plugin').default

const env = process.env.NODE_ENV === 'testing'
    ? require('../config/test.env')
    : require('../config/prod.env')

const webpackConfig = merge(baseWebpackConfig, {
    // module,css
    module: {
        rules: utils.styleLoaders({
            sourceMap: config.build.productionSourceMap,
            extract: true,
            usePostCSS: true
        })
    },
    devtool: config.build.productionSourceMap ? config.build.devtool : false,
    output: {
        //
        path: config.build.assetsRoot,
        //
        filename: utils.assetsPath('js/[name].[chunkhash].js'),
        //,
        chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
    },
    plugins: [
        // http://vuejs.github.io/vue-loader/en/workflow/production.html
        new webpack.DefinePlugin({
            'process.env': env
        }),
        new UglifyJsPlugin({
            uglifyOptions: {
                compress: {
                    warnings: false,
                    //UglifyJsPlugin console
                    // drop_console: true,
                    // pure_funcs: ['console.log']
                }
            },
            sourceMap: config.build.productionSourceMap,
            parallel: true
        }),
        // extract css into its own file
        new ExtractTextPlugin({
            filename: utils.assetsPath('css/[name].[contenthash].css'),
            // Setting the following option to `false` will not extract CSS from codesplit chunks.
            // Their CSS will instead be inserted dynamically with style-loader when the codesplit chunk has been loaded by webpack.
            // It's currently set to `true` because we are seeing that sourcemaps are included in the codesplit bundle as well when it's `false`,
            // increasing file size: https://github.com/vuejs-templates/webpack/issues/1110
            allChunks: true,
        }),
        // Compress extracted CSS. We are using this plugin so that possible
        // duplicated CSS from different components can be deduped.
        //cssExtractTextPluginjs(css)
        new OptimizeCSSPlugin({
            cssProcessorOptions: config.build.productionSourceMap
                ? { safe: true, map: { inline: false } }
                : { safe: true }
        }),
        // generate dist index.html with correct asset hash for caching.
        // you can customize output by editing /index.html
        // see https://github.com/ampedandwired/html-webpack-plugin
        //html,cssjs
        new HtmlWebpackPlugin({
            filename: process.env.NODE_ENV === 'testing'
                ? 'index.html'
                : config.build.index,
            template: 'index.html',
            inject: true,
            minify: {
                removeComments: true,
                collapseWhitespace: true,
                removeAttributeQuotes: true
                // more options:
                // https://github.com/kangax/html-minifier-sharpoptions-quick-reference
            },
            // necessary to consistently work with multiple chunks via CommonsChunkPlugin
            chunksSortMode: 'dependency'
        }),
        // keep module.id stable when vendor modules does not change
        new webpack.HashedModuleIdsPlugin(),
        // enable scope hoisting
        new webpack.optimize.ModuleConcatenationPlugin(),
        // split vendor js into its own file
        new webpack.optimize.CommonsChunkPlugin({
            name: 'vendor',
            minChunks (module) {
                // any required modules inside node_modules are extracted to vendor
                return (
                    module.resource &&
                    /\.js$/.test(module.resource) &&
                    module.resource.indexOf(
                        path.join(__dirname, '../node_modules')
                    ) === 0
                )
            }
        }),
        // extract webpack runtime and module manifest to its own file in order to
        // prevent vendor hash from being updated whenever app bundle is updated
        new webpack.optimize.CommonsChunkPlugin({
            name: 'manifest',
            minChunks: Infinity
        }),
        // This instance extracts shared chunks from code splitted chunks and bundles them
        // in a separate chunk, similar to the vendor chunk
        // see: https://webpack.js.org/plugins/commons-chunk-plugin/-sharpextra-async-commons-chunk
        new webpack.optimize.CommonsChunkPlugin({
            name: 'app',
            async: 'vendor-async',
            children: true,
            minChunks: 3
        }),

        // copy custom static assets
        new CopyWebpackPlugin([
            {
                from: path.resolve(__dirname, '../static'),
                to: config.build.assetsSubDirectory,
                ignore: ['.*']
            }
        ]),

        // Make sure that the plugin is after any plugins that add images
        new ImageminPlugin({
            disable: process.env.NODE_ENV !== 'production', // Disable during development
            pngquant: {
                quality: '95-100'
            }
        })
    ]
})

if (config.build.productionGzip) {
    // ,.gz
    const CompressionWebpackPlugin = require('compression-webpack-plugin')

    webpackConfig.plugins.push(
        new CompressionWebpackPlugin({
            asset: '[path].gz[query]',
            algorithm: 'gzip',
            test: new RegExp(
                '\\.(' +
                config.build.productionGzipExtensions.join('|') +
                ')$'
            ),
            threshold: 10240, // 10240B=10kB
            minRatio: 0.8 // 0.8
        })
    )
}

if (config.build.bundleAnalyzerReport) {
    const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
    webpackConfig.plugins.push(new BundleAnalyzerPlugin())
}

module.exports = webpackConfig