General developer forum

Changing folder and/or file permissions from 755 to 777 will NOT corrupt the files or folders who's permissions you are changing.
File or folder permissions are divided into three catagories of users who may need to access the file or folder, these are Owner, Group and other.
An example of file permisssions set to 755;
Owner can Read, Write and Execute
Group can Read, Execute but not Write (they cannot change the content of the file directly)
Other can Read, Execute but not Write (they cannot change the file content directly)

File permissions set to 777 indicate that;
Owner can Read, Write and Execute
Group can Read, Write and Execute
Other can Read, Write and Execute