Steam Deck will allow you to pause the game and continue it on another device from the same place

Steam has announced a new dynamic cloud sync feature for the Steam Cloud as part of Valve's preparations for the release of Steam Deck. This feature will allow players to switch between Steam Deck and PC without losing game progress.

Thanks to the sync feature, Steam automatically uploads saved game data to the cloud before the device goes to sleep, allowing players to continue playing on the other device where you left off, and if you later return to Steam Deck you will continue from the last save you created .

The only problem is that it's not a built-in feature: developers will need to manually add it to their games, although Valve recommends this to "give players the best possible experience." If this feature is not enabled, Steam Deck will still sync saves to Steam Cloud, but only when the device is on and without save updates when it goes to sleep.

A source: Steam