chmod

chmod command means change mode.chmod is used to alter the permission of files and folders. There are three basic modes to files and directories: read, write, and execute. Additionally, each of these modes can be applied to the user, the group, or others.If chmod is used without any option, it alters the permission of the file/folder specified. To alter only the read, write or execute permission the user have to add the necessary arguments along with that command.