Where can I find information on these buttons?

I would like to understand what happens when I click following buttons ?

< number> but in a vertical arrangement and below a grey or green appearing circle with a white check mark in it
The buttons are on right top corner of an answer in this forum.

To view what does a button or a menu entry, the best way I know is to enable extended tips (menu Tools > Options > LibreOffice > General). Then you get an help tip when you move the mouse pointer on the button or the entry menu.

If you mean the arrows above and below the "current number of votes":

(Screenshot from → How do I mark the best answer to my question on this site?)

The "up arrow" is for upvoting an answer/question [+10 “karma points”],

the "down arrow" is for downvoting an answer/question [-1(?) “karma point”].

See also:

FAQ · How does karma system work?

Why are answered questions showing up as Unanswered?

Thanks for the excellent answer. However, looking at your screen shot I got jealous because my browser doesn’ t the little text window "mark this answer…
May I propose to add this information with the picture into the FAQ · How does karma system work?. I read there, but did not find the explanations for the buttons. (Or I might need glasses!!!)

@ jean-baptist
Also thanks to you. However, the extended tool tips in LibO don’t work here. I tried it. I also had a look at my browser (Firefox) but didn’t find a possibility to display tool tips.

It’s me, I misunderstood your question, I did not understand that it was not about LibreOffice but about askLibO

`@Jean-Baptist No problem. you just made my brain exercise a bit more…