The permissions on a file or folder specify how it can be accessed. These permissions apply to the basic user types as well as to the ACL default types described in "Setting Default Permissions Through an Access Control List".
Read Permission - Allows access to retrieve, copy, or view the contents of the object.
Write Permission - For a file, allows access to change the contents of the file. For a folder, allows access to create or delete objects from the folder.
Execute Permission - For a file, allows access to run the file (for executable files, scripts, and actions). For a folder, allows access to search and list the folder's contents.
If you do not have permission to write inside a folder, the folder will look like this:
If you do not have read or execute permission for a folder, the folder will look like this: