"...Hope these explanation clear your doubt."
Here it goes !!!
Providing Read/Write Access to the Share
Another problem with mounting the Windows share as permanently entered in the /etc/fstab file
//servername/sharename /mountdirectory smbfs username=windowsuserename,password=windowspassword 0 0
is that only the root user would have read/write access to the share. All other users would have read only access to it. If you wanted read/write access to it for yourself, you need to specify your userid or groupid. That would change the line in /etc/fstab to look like this:
//servername/sharename /mountdirectory smbfs credentials=/home/myhomedirectory/. smbpasswd,uid=mylinuxusername,gid=mylinuxgroupname 0 0
Whatever user and or group you specified in the line would have read/write access to the mounted share. You can use either the user or group name or the user or group numerical ID. Either should work.
If you had several users you wanted to have read/write access to it, create a group and add those users to the group. Then specify just that groupid in the /etc/fstab file. You wouldn't need to specify a userid. The line in etc/fstab would look like this:
//servername/sharename /mountdirectory smbfs credentials=/home/myhomedirectory/. smbpasswd,gid=sambausersgroup 0 0
You can see the man pages on smbmount, smbumount, mount, and fstab for more details.