Servlets are pure java programs.here we can't use HTML.
But in JSP we use HTML,so we can use and modify the data 
very easily.
   Servlets are faster than JSP.bcoz while running JSP 
programs it will be converted into Servlets and then 
executed,so it takes more time.

Servlets are pure java codes,here we can't used HTML.
But in JSP we can use HTML,so we can modify and also 
updated the data.
Another difference In Servlet  clientside validation is 
possible But in jsp clientside validation is not possible.

Both servlet and jsp are web components. But servlet is 
best suited for request processing, handling the business 
logic while jsp is suitable for content generating .Its 
easy to include html tag in jsp rather than servlet.Also 
jsp is compiled to servlet when first loaded to 
webserver.So in many framework servlet act as a controller 
while jsp as a view.Also implicit object and action 
elements available in jsp but not in servlet.

Jsp is better for preparing presentation pages, while 
servlet is good for request processing as it's more 
difficult to write include, forward a static or dynamic url 
with in out.println() ,

Jsp has also all implicit objects, we need not have to 
instantiate any which is easier.

error handelling is easy in jsp isErrorPage="true" 
errorPage="/page"

we need not have to bother about init(),service(),destroy
(),doGet(),doPost()in jsp.

in servlet for each time changing we have to explicitly 
compile it.

Jsp automatically compiled by container when we reload the 
page.

Jsp mainly used for the presentation only.It support only 
Http. whereas servlet support FTP,Http etc

1-The most important difference is that whenever we do some
changes in a servlet we need to build the application
completely but no need to do the same in case of jsp....