How do websites such as Love Station Network and webmaster's Home get the seo information of a certain website?

how do websites such as Aizhan.com get the seo information such as the PR value and alexa ranking of a website?

Seo
Mar.01,2021

this information is public, but these sites are aggregated.

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1bfbfa9-3229a.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1bfbfa9-3229a.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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