note: Visual mode may be more intuitive than Vim's Normal mode of operation, but it has a weakness: it doesn't always play well with the dot command.
select the inner contents of a tag
it
command is a special kind of motion called a text object.
converts the selected characters to uppercase
The Visual mode
U
command has a Normal mode equivalent:gU{motion}
vitU
can be considered as two separate commands:vit
to make a selection andU
to transform the selection.gUit
can be considered as a single command comprise of a operatorgU
and a motionit
.