Why vapour are same as gas?

Answer 1

Vapour and gas are not same.A substance which under ordinary conditions is a solid or a liquid,but under specific conditions is gaseous is called a vapour. For example,water vapour,sulphur vapour,etc.

However, a substance which under ordinary conditions is gaseous ,is called a gas.

for example,Oxygen,Nitrogen,etc

Answer 2

Vapour and gas both refer to the gaseous state of a substance. The term "vapour" is typically used when talking about a substance in its gaseous state at a temperature below its boiling point, while "gas" is a more general term for any substance in its gaseous state. In essence, vapour and gas can be used interchangeably depending on the context.