What is the key difference between an absolute path and a relative path in Unix file systems?

$1-$ An absolute path does not require a leading $/,$ while a relative path always starts with $/.$

$2-$ An absolute path starts with the present directory, while a relative path starts with $/$ and traces the entire path from the root directory.

$3-$ An absolute path always starts with $/$ and points to a specific file, while a relative path does not specify the file location.

$4-$ An absolute path starts with $/$ and traces the entire path from the root directory, while a relative path starts with the present directory.