Cannot vs. Can Not [duplicate]

What's the difference between "cannot" and "can not?"

Don't they mean the same? It's kind of crazy if they don't.

We learned all about it in 6th grade, but you know how that goes: in one ear and out the other.

OED-cannot definition: the ordinary modern way of writing can not

Both cannot and can not are acceptable spellings.

There’s no difference in meaning between cannot and can not. but the cannot is much more usual.

Some references from ELU - can't vs cannot

Why is “cannot” spelled as one word?..(a few exceptions)

They do mean the same thing, but common usage over time has made one form more "usual" than the other (namely cannot). It's similar to contractions (can't, don't, won't), except it seems acceptable to use cannot in a formal setting whereas contractions are frowned upon.

Source: http://www.dailywritingtips.com/cannot-or-can-not/