chmod 775-rwxrwxr-x
chmod 775 gives the owner and group full read, write, and execute access, while everyone else can read and execute but not modify — the directory-friendly counterpart to 664.
Owner
You, the file's creator
Group
Everyone in the file's group
Public
Everyone else on the system
Special permissions(advanced, rarely needed)
Common presets
On a file, 775 lets the owner and the file's group edit and run it, while everyone else can read and run it but not change it. It's less common on files than 664, since the execute bit only matters for scripts and binaries.
On a directory, 775 is genuinely useful: the owner and anyone in the group can create, rename, and delete files inside, while everyone else can enter and browse it but can't modify its contents. This is the standard mode for a shared deployment or project directory managed by a small team via a common group.
When to use chmod 775
Use 775 for directories a defined group needs to collaboratively write to — a shared release folder, a project directory edited by a small dev team, or a path where a web server's user and a deploy user share group ownership.
Security notes
As with 664, 775's safety depends on tightly controlling who belongs to the file's group, since every member gets full write access to everything inside. It's broader than 755 in exactly that one way — 755 grants no write access beyond the owner, 775 extends it to the whole group.