If you choose public liability insurance you are covered for damages that you are responsible to pay if a person is injured or possessions are damaged as a result of you operating your painters and decorating business. For example, you leave the top of a tin of paint lying around and somebody steps on it and then onto a carpet. The building or home owner takes an action against you and it is found that you are liable for the damage to the carpet. Or, for instance, somebody falls over a paint brush and breaks a leg. They take an action against you because your equipment caused them to fall and injure themselves. Your public liability policy will pay your defence costs and any subsequent award.
If you also have employer’s liability cover, it covers you against accidents employees may have while working for you.