It's called "Texting" or "IMing" or more formally "SMS Language" and it refers to the sometimes complex language of abbreviations and acronyms that teenagers and others use to communicate via cell phone Text Messages and online Instant Messages.
Here are some examples:
lol
=
laughing out loud
RUOK?
=
Are you OK?
dis
=
this
BRB
=
Be Right Back
whr
=
where
xlnt
=
excellent
ASL?
=
age, sex, location
gr8
=
great
MOS
=
Mom Over Shoulder
any1
=
Anyone
5o
=
Police
9
=
Someone's watching me
This is the language of chatrooms, cell phones, instant messaging and digitally connected teenagers everywhere. It's function is to minimize the number of key strokes and punctuation needed to communicate a message. It's officially called Short Message Service or SMS Language and here's a link to more information about it's development: Short Message Service