when you click in the terminal, it can either be handled by

your terminal emulator
(represented by a box with a winky cursor face and little arms and legs)
(good if you want to copy text)

or

the program
(represented by a box with a smiley face)
(lots of programs have mouse support!)

programs can tell the terminal emulator to let them handle the mouse

program: if there’s a mouse click, send me escape codes to tell me where it was!

terminal emulator: okay! I’ll disable all my usual mouse functions like “selecting text”!

this is called “mouse reporting”

some programs that have mouse support

• tmux: resize a pane! right-click for a menu!
• htop: click to sort columns!
• micro: text editor with good mouse support
• vim: click on the tab bar!
• and lots more! (lazygit, mc, zellij, btop…)

how to force the terminal emulator to handle the mouse:

unhappy stick figure with short curly hair, thinking: ugh no I don’t want to focus that pane, I want to COPY SOME TEXT!!!

• could be something else too, it depends on your terminal emulator

the scroll wheel

In some programs (like less) the scroll wheel does the same thing as pressing up/down arrow keys really fast

terminal emulator: UP UP UP UP UP UP UP UP UP UP UP UP

in other programs (like lazygit) it uses “mouse reporting” to report where your mouse was when you scrolled

other mouse features your terminal emulator might have

• Shift+click (or something) to open a link in a browser
• Alt+click (or maybe Option) to move the cursor when editing a command in your shell