Without any text it's really hard to guess what you want and that's why you get so many different questions.

Do you want to

• host a copy of wikipedia for yourself locally? Then download the database from https://en.wikipedia.org/wiki/Wikipedia:Database_download (thanks zygo_histo_morpheus) and the sofware from https://www.mediawiki.org and get going. Both are freely available
• host a site that works like wikipedia but doesn't contain its content, but your own? Just use MediaWiki.
• host a wiki, but not necessarily the one that powers wikipedia? Then pick one from https://github.com/awesome-selfhosted/awesome-selfhosted?tab=readme-ov-file#wikis

Note that I suspect you actually want the third one, in which case I suggest you avoid MediaWiki. Not because it's bad, but because it's almost certainly overkill for your use-case and there's way simpler, easier-to-setup-and-maintain systems with fewer moving parts out there.

I have a the logo of the Wikipedia right in the post, and I explicitly say Wikipedia, not wiki, not a knowledge database 🫣

I'm sorry that my attempt to find out what you want to be able to provide useful help annoyed you.

Not annoyed, but many other people understood what I meant, and your suspicion was not correct, although I really used name Wikipedia explicitly (also, the image is PNG, it has word Wikipedia, but Lemmy decided to not show it, but when I was attaching it, it was showing)