Difference between Free and Refresh

Hi,

I know that Refresh or clear deletes the content of an internal table but memory allocation remains.So we can use that same internal table in another purpose.

Whereas I studied that Free deallocates the memory and the internal table cannot be used after we freed the internal table using Free:Itab. But I used the internal table(filled the internal table with data) after the free syntax. It doesn't show any error or dump.

Can anyone please explain what's the difference between Free,Refresh,clear?

Regards,

Arjun