Those are text editors.
B and I are BOLD and ITALICS
The globe hyperlinks,
the quotation marks block quote,
The brackets create code blocks,
And the picture inserts an image, and I don't have one... T.T
- The number list creates a numbered list.
- The bullet list creates a bullet point list.
The thing with a line above makes a header.
Click it twice to make a bigger header.
The other thing makes a horizontal line. ^^^
The other two are undo and redo buttons.
(You could find all this out by hovering over those icons with your mouse, btw.)