 <p>classpath and path are the evironment variables . usually , you have to put the jdk/bin to path so that u could use java compiler everywhere , classpath is the path of your .class files . the classpath has a default path a period(.) which means the current directory. but when u used the packages . u would either specify the full path of the .class file or put the .class file path in the classpath which would save a lots of works ! </p>