A Web server exclusively handles HTTP requests, whereas an application server serves business logic to application programs through any number of protocols.

Webserver mainly handles the Http requests but APP server can be used to handle the http, rmi, TCP/IP and many more protocols. Webserver just handles the requests of the webpage - means suppose, a html page(presentation LAYER) requests a data - here script is written containing the business logic , then it just give the response with the required data from the database. Then the html page with script is used to show the retrieved information. In case of application server, it does the same thing, of getting and gives the response but it can process the requests. i.e. in this case, instead of script know how to fetch the data, the script is simply used to call the applications server's lookup service to retrieve and process the data. i.e here, application server is used for processing/applying logic. The web server can be considered as the subset of app server

The BASIC difference between a web server and an application server is WebServer can execute only web applications i.e. servlets and JSPs and has only a SINGLE container known as Web container which is used to interpret/execute web applications Application server can execute Enterprise application, i,e (servlets, jsps, and EJBs) it is having TWO containers 

1. WebContainer (for interpreting/executing servlets and jsps)

2. EJB container (for executing EJBs). 

It can perform operations like load balancing , transaction demarcation etc

A Web server exclusively handles HTTP requests, whereas an application server serves business logic to application programs through any number of protocols.

Webserver mainly handles the Http requests but app server can be used to handle the http, rmi, TCP/IP and many more protocols. Webserver just handles the requests of the webpage - means suppose, a html page(presentation layer) requests a data - here script is written containing the business logic , then it just give the response with the required data from the database. Then the html page with script is used to show the retrieved information. In case of application server, it does the same thing, of getting and gives the response but it can process the requests. i.e. in this case, instead of script know how to fetch the data, the script is simply used to call the applications server's lookup service to retrieve and process the data. i.e here, application server is used for processing/applying logic. The web server can be considered as the subset of app server

The basic difference between a web server and an application server is WebServer can execute only web applications i.e. servlets and JSPs and has only a single container known as Web container which is used to interpret/execute web applications Application server can execute Enterprise application, i,e (servlets, jsps, and EJBs) it is having two containers 

1. WebContainer (for interpreting/executing servlets and jsps)

2. EJB container (for executing EJBs). 

It can perform operations like load balancing , transaction demarcation etc