This topic is examined in A-Level Paper 3 and Paper 4 for WJEC (Wales) Economics. You can find notes for it below:

Costs, Revenues and Profits

a) Costs, revenues and profits
b) The growth of firms
c) Efficiency

Market Structures

a) Background to market structures
b) Business objectives
c) Perfect competition
d) Monopolistic competition
e) Monopoly
f) Oligopoly
g) Competition policy
h) Privatisation