Terms you should be able to define

1. Back-checking
2. Backtracking (chronological, intelligent)
3. Complete solution (global solution)
4. Completeness (of an algorithm)
5. Consistent solution
6. Expansion (of a node in a tree)
7. Forward checking
8. Instantiated variable
9. Partial solution
10. Pruning
11. Soundness (of an algorithm)
12. Thrashing