the front end has been learning for some time, from the initial html,css,js, to the later jq,vue. At the beginning of learning vue is to write data in data, which is very slow and tedious. Later learn to copy and paste the online data in the json file, that is, mock a local data. Then later learned to use axios online crawl other people"s website interface, with express proxy or jsonp crawl. I am looking for some ui,. A web page will be finished soon. But the problem also follows. There is a problem in crawling the data of other people"s websites with axios, and there is a problem after packaging, so there is no way to get the data. Because I don"t understand the back end, I don"t know what"s going on when I say I want to reverse proxy, but there is no problem with the data obtained with jsonp. In short, there are a lot of problems, and sometimes the interface fails, so it is necessary to rewrite the interface format. What I think now is that I can write my own interface at the back end, and then I get it at the front end. I no longer crawl the interface of other people"s websites. I have my own data and have my own website. For example, when I was studying the vue music website, I used an interface https://c.y.qq.com/splcloud/f., which is an interface of QQ Music with recommended music data. Crawled with axios and express. I hope that after learning the backend, I can provide such an interface by myself, and then pack it online and still use it, instead of using someone else"s interface. I bought both the domain name and the cloud server. I don"t understand what the back end may say is a little funny, but I really ask. I hope that after learning the back-end 1, I can understand some agent problems, because before using axios to obtain other people"s website data, after packaging, it is invalid. I think what I say most is how you should act as an agent. 2, you can write your own interface data for your own use, and no longer use the interfaces of other people"s websites. At present, there is a bit of a tendency to learn node.js and express. I hope you can give me some advice. Probably what knowledge to learn, as well as the learning path