Absolute path means we have to mention full path in script.

Example: executefile "E:\project name\libraries\main.vbs"

Relative path menas no need to give full path just mention 
file name

Example: executefile "main.vbs"

But here if you want to convert this Absolute file path as 
relative path. you should do following steps

Tools menu-->options-->folders tab

here you have to add this path example "E:\project 
name\libraries"

then you can use direct filename as above mentioned in the 
relative path example instead of absolute path example.