Intent

A proxy controls access to the original object as It provides a substitute or a placeholder for another object to save time or resources when it costs a lot to access it. The proxy could interface with anything.

Problem

Imagine that we have an object consuming a huge amount of system resources, and we need to use it sometimes.
There is a problem that it is stored on a computer in another place and we can access it using the internet, but we have a problem that our internet speed isn't fast so we want :

To make sure that this object is available before making some effort to try to access it.
To use some temporary data (if there were a high necessity) if this object isn't available for any reason.

So how can we do that?

Solution

Here comes the role of the proxy design pattern that works as a bodyguard to allow allowed people to access the resources while others do not, and it represents that important person that he protects when it is not there.