Question

what is a jar file in java?? what is the use of converting the java programs into a jar file?? can we make a java project into an installable software??

Answer 1

jar files are the stand alone files that gets executes with java compatible machines,also jar files are bestused on portable devices such as mobiles.converting .java to jar makes it a executable format.
for further investigation go to: http://docs.oracle.com/javase/1.3/docs/tooldocs/solaris/jar.html

Answer 2

jar (Java ARchive) is basically Java''s implementation of tar (Tape ARchive). It globs directories into a single file. Projects can be packaged into a jar file, but the jar will be extracted so the program files will be files when they execute.