Permissions help the server determine which users have the ability to read, write or execute files or folders. More precisely, file permissions include the ability of viewing, editing and running the file as a script, respectively. Folder permissions include viewing the content, adding or removing the files or performing some other actions on the folder.
Setting folder :
find . -type d -exec chmod 0775 {} \;
Setting files :
find . -type f -exec chmod 0644 {} \;