Alot

Alot:
Not actually a word in the English language.

Allot:
To assign or distribute for a specific purpose.

Lot:
1. A great number or quantity.
2. Role in life
3. Collection of similar things

A lot:
Two words that when used together mean an unspecific large number or ammount.

I ate a lot of Ice Cream this summer.
or
There sure are a lot of people at the hockey game.

The use of the non-word "alot" is one of my biggest pet peeves.