The advantages of deploying Application Layer:
It is the Intermediate layer in between the Client and the Server. It is installed with a database client to communicate with the database server i.e. all the clients are freed with DB Clients.
Application server/ layer handle the request and process them based on FIFO (First in and First out). It has its own queue mechanism to process the user request. It also contains the task interpreters to interpret the user request and route it to the server.
It is intelligent to store the frequently accessed data thereby reducing the load on the server.