Garry's Mod is a physics sandbox. It's an indie simulation game developed by Facepunch Studios and published by Valve in 2006. There aren't any predefined aims or goals. We give you the tools and leave you to play.
System requirements for desktop computers as stated by the developer. Updated on February 25, 2020.
The system requirements are modest, but it's recommended to have a dedicated graphics processing unit for successfully playing Garry's Mod. GeForce GTX 580M or better mobile GPU is needed.
Most gaming laptops meet the RAM requirement of 8gb, though 4gb is enough to meet the minimum requirements.
Also, note that at least 5gb of disk space is needed.