Component testing using mstest

I am new to testing. I know that unit testing is used to test the smallest units of an application like methods or functions, and mstest.exe can be used to run unit tests. I wanna know what exactly component testing is, and what is the different between component testing and integration testing? In a real world scenario like an online store, what are the component tests and how do we do component testing in Visual Studio? Do we use mstest?