What is the actual difference between sub queries and multiple queries.?

Answer 1

Well a subquery is a query whichs result is taken and put in the Main query
das you want to Select every employee with an average wage ans above. So in the subquery you get the average wage. The result is put into the Main query that selects the employee. Hope i explained well enough

note:
you can only do the example with subquerys

Answer 2

yup..
thank you sir..
u have cleared my doubt.

Answer 3

subquery : it's a query within query which has execution way is first the inner queries get executed and the result is passed to the outer queries then after the outer queries gets executed

hope you got that