Question

What is meant by the terms managed resource and unmanaged resource in .NET? How do they come into the picture?

Answer 1

The term “unmanaged resource” is usually used to describe something not directly under the control of the garbage collector. For example, if you open a connection to a database server this will use resources on the server (for maintaining the connection) and possibly other non-.net resources on the client machine, if the provider isn’t written entirely in managed code.

This is why, for something like a database connection, it’s recommended you write your code thusly:

using (var connection = new SqlConnection("connection_string_here"))
{
    // Code to use connection here
}

As this ensures that .Dispose() is called on the connection object, ensuring that any unmanaged resources are cleaned up.