A world that is used primarily on internet site.
It cannot be found in the dictionary and drives many people crazy as it is incorrect.

Allot means to share/ divide space or things- this is where allotment came from, an allotted space of land.

lot- meaning one of a set of objects/ a way of deciding (similar to vote) or the decision or choice made by such a method.

a lot- Very many, a large number; also, very much.

Now, the word 'alot' doesn't appear in any correct dictionary, so it is not a word. It is a popular misspelling- done by those who seem to have missed basic spelling classes in Primary school.