Startup class is responsible for managing/registering of two essential components of your application, namely 

• the middleware pipeline 
• the implementation of service registration.

 

Services
Your application is dependent on services, which are classes written in C#, in order to provide additional functionality. These services are utilized by both the framework and your application. 

• In order for these services to be instantiated when your application is running and when it requires them, they must first be registered.
• There are several examples, such as logging and get data from database

 

Middlewre Pipeline

• It is the sequence in which application handles an HTTP request 

 

Methods in Startup Class

ConfigureServices() and Configure() are the two methods that are contained within the Startup class. 

• ConfigureServices method,  is responsible for registering all of the services that the application requires. 
• Configure method, Handle Middleware pipeline configuration