Folks,

This may be simply and very old question to some of you, but please let me know the Basic or Main Difference between a variable declared without "extern" keyword and with "extern" keyword??????

Here is the scenario:
1. ------> I have declared a variable int glo_var; in Test.h and including Test.h in different files. ex: Test1.c, Test2.c, Test3.c and i could able to Read/Modify the variable glo_var without any problem.

2. -------> I have declared a variable extern int glo_var; in Test.h and including Test.h in different files. ex: Test1.c, Test2.c, Test3.c and i could able to Read/Modify the variable glo_var without any problem.

I had gone through the difference websites to know about this, but i couldnt get main difference, please let me know the difference as much as detail.

Thanks in advance.