1. Differences between interface & absrtact class?
a)Interface:-
They contain the method declarations and you need to implement them
compulsorily.
Abstact classes:-
In abstract class both method declarations and definitions are also
allowed.
You need not implement all the methods in the sublass as in interface.

You cannot create an object for abstract class.

2.diffrences between servlets & jsp?

Servlets are html within java  code
Jsp are java within html code.If we strictly observe the life cycle of jsp  ,a
jsp program will be converted to a servlet  program in runtime.nothing but a jsp
is a servlet program in disguise.

Servlets are used when data  is imp.
Jsp are used when Presentation is imp.


3. if ten threads r of same priority which will run first?
Thread concepts in theory wise is ok.when comes to practical wise,
we cannot predict which thread will come first .