How to select or highlight a block in Emacs?
I want to select or highlight a block in emacs without using mouse but doing it from the keyboard like vim's visual mode. What is the easiest way to do this from a keyboard?
Answer
If I understand the question correctly, it is not about rectangular regions originally.
C-Spc puts a mark at the current position.
Wherever your cursor is afterwards, the text between the last mark and the current position is "selected" (you can highlight this by activating transient-mark-mode, but this will also mean that marks have to be deleted when you don't want highlight).
You can operate on that region with commands like:
C-w . . Kill region. This deletes and puts the region into the kill ring.
C-y . . Yank. This inserts the last snippet from the kill ring.
M-y . . Cycle kill ring. Immediately after C-y, this replaces the yanked part by the other snippets in the kill ring.
M-w . . Save region into kill ring. Like C-w, but doesn't delete.
This is just the basic usage. Marks have other uses, too. I recommend the tutorial (C-h t).