The systems binaries are only writable by the root user to prevent malicious changes. The unixy parts of OSX are the same as they are based on systems designed

The systems binaries are only writable by the root user to prevent malicious changes. The unixy parts of OSX are the same as they are based on systems designed to safely accommodate multiple users. Unlike Linux, OSX has been considerably updated to accommodate the modern single user desktop. There are application bundling schemes for Linux applications that take a similar approach to OSX bundles but they are not widely used.