A lookup table stores items you are going to want to use in another table. Like let's say you have types of computer equipment. You would have those types in a lookup table:
Code:
EquipID EquipType
1 Monitor
2 CPU
3 RAM
4 Hard Drive
5 Keyboard
6 Mouse
Etc.
and then a transaction table is something that stores information about a certain "event" so-to-speak. If you have received a check, you would store that information in a transaction table. If you have an order, that would go in the orders and order details tables.
So does that help?