Explain what are the other two options for bidding other than C-P-C?

There are five types of flexible bid strategies:
1.Maximize clicks: This is a flexible version of the Automatic CPC bidding strategy.
2.CPA bidding: This is a flexible version of Conversion Optimizer used in the target CPA (average CPA) capacity.
3. Enhanced CPC: Flexible version of the existing enhanced CPC capability.