A type of public bill that is introduced by an individual MP or lord that are NOTGovernment Ministers. Their main purpose is to change or make laws that apply to a general population. Very few actually become Acts of Parliament.
Private Members Bills can be introduced in one of two ways:
By Ballot - where 20 private members are selected to present their Bill to Parliament. There is limited time given to these in Parliament, and realistically only 6 or 7 get heard.
By Ten-Minute Rule - which allows any MP the opportunity to make a speech for up to 10 minutes, introducing the bill and proposed law. But these are often unsuccessful e.g. Abortion Act 1957.
Public Bill :
Will involve matters of public policy that will either effect the whole country or a large proportion. The majority of bills that are created by the government will be public bills.
E.g. PACE 1914
Private Bills :
These are limited to a number and are designed to pass a law that will only affect individual people or corporations. These do not affect society as a whole.