All right can mean different things depending on the context.
1. Permissible -- Is it all right if I work late tonight?
2. Satisfactory -- I found his comedy to be only all right.
3. To reinforce a declaration -- It's cold out, all right.
4. OK -- Are you feeling all right?
5. All correct -- My answers on the test were all right.
Alright remains to be a source of grief. Technically, it is NOT a word. However, people use it so frequently that I fear it is slowly gaining acceptance. I consider this poor spelling.
Remember: Poor spelling is not something that must be lived with. With a little work, it can be greatly improved.