A
feature of a
text editor which displays different parts of
syntax for types of
code in
different colors,
fonts, and/or
styles. The
intention it to make it more
apparent what a section of
code is and what it
does by just being able to
glance at the editor.
It also helps catch some errors. For example, the lack of a second quotation mark (") on a string will cause long sections of code to show up as belonging to the string, making the error quite apparent. This also applies to comments.
After you get used to using it, you'll find it difficult or impossible to switch back.
Many IDEs have it, and a number of text editors, such as emacs, also have it.