After installation of Laravel you will require to configure some folder permissions. Currently till Laravel version 5.2 we require to set the permission of 2 folders.
These both folder need writable permission. Because we write the logs in storage folder and save cache in bootstrap/cache folder. Most of the developers set permission 777 to these folders.
Never ever set permission 777 to the folders until it is required. If you are giving 777 permission you are allowing anyone to Read, Write and Execute the files. If you are giving writable and executable permission then it's big security concern. ...