What does this sign mean on twitter > or <?

[Yellowburd]

I've lately been noticing people tweet something and then put this < or > at the end of their tweet
for eg one writes " headache << " please explain in detail what it means, an example would also be nice, Thanks

[Big Bone!]

> more than
< less than

[more ">"] or [less "<"]

> or <


is math symbols used in a conversation..
4 is more > than 2
4 > 2

some people use that expression "more or less" when trying to express an opinion or trying to understand something...