Explain what is meant by the term value?

Value is the worth of something.

It can either be objective or subjective. For example the value of a coin is easy to determine as it has a "face value", however, an old photo may have a subjective value (e.g. "priceless") as it holds value to the owner.

Other terms such as "value engineering" simply mean looking for ways to reduce costs on a project.

"Value you your opinion" means that the input or contribution of a person is sought after.