Valve has officially introduced an integrated game recording system, available for free to Steam users. Currently, the feature is in beta testing.
This system allows users to record, edit, save, and share videos without the need for third-party software. Recording can be done in the background or triggered by a hotkey. The recorded gameplay will be immediately available for viewing and editing in the Steam “Recordings and Screenshots” section.
Users also have access to a timeline feature with special markers – this allows marking important moments in the video. As of the start of the beta testing, timeline markers are supported only in Counter-Strike 2 and Dota 2.
According to Valve's official announcement, the game recording function is designed to use as few resources as possible from the running game – it leverages the capabilities of NVIDIA and AMD graphics cards for this purpose. Users can also enable audio recording from other programs and control the size of the recorded videos.
To activate the new feature, go to "Settings" > "Interface" > "Participation in Beta Testing" and select one of the beta versions; then go to "Settings" > "Game Recording" and choose either background recording or recording on demand.