Enzyme induction is a process in which a molecule (e.g. a drug) induces (i.e. initiates or enhances) the expression of an enzyme.
Enzyme inhibition can refer to 
* the inhibition of the expression of the enzyme by another molecule
* interference at the enzyme-level, basically with how the enzyme works. This can be competitive inhibition, uncompetitive inhibition, non-competitive inhibition or partially competitive inhibition.
If the molecule induces enzymes that are responsible for its own metabolism, this is called auto-induction (or auto-inhibition if there is inhibition). These processes are particular forms of gene expression regulation.
These terms are of particular interest to pharmacology, and more specifically to drug metabolism and drug interactions. They also apply to molecular biology.