Protected procedure call
When we are visiting a friend's house, we usually knock on their door and wait for them to come and open it. In the same way, when a computer program wants to use some special functions, it has to ask for permission first by calling them. This is called a procedure call.
Now, imagine if someone wanted to use some secret or private functions that shouldn't be accessible to just anyone. To protect these functions from unauthorized use, the programmers decided to add a guard to each of these functions. This guard checks if the person calling the function has the proper permission to use it.
So, before the program can use a protected function, it has to go through this guard to get the permission. If the program has the permission, then it gets to use the function. But if it doesn't have the permission, it won't be able to use the function and will be denied access.
So, in simple terms, a protected procedure call is a way of making sure that only authorized people, such as the program itself or specific users, can use certain functions within the program. It's like having a guard at the door of a special room that only certain people are allowed to enter.
Now, imagine if someone wanted to use some secret or private functions that shouldn't be accessible to just anyone. To protect these functions from unauthorized use, the programmers decided to add a guard to each of these functions. This guard checks if the person calling the function has the proper permission to use it.
So, before the program can use a protected function, it has to go through this guard to get the permission. If the program has the permission, then it gets to use the function. But if it doesn't have the permission, it won't be able to use the function and will be denied access.
So, in simple terms, a protected procedure call is a way of making sure that only authorized people, such as the program itself or specific users, can use certain functions within the program. It's like having a guard at the door of a special room that only certain people are allowed to enter.