Source: Valve
It'll now be easier to keep other people from accessing your Steam Deck without your permission. Valve updates the handheld gaming PC to let you set a PIN for the lock screen. When you've installed the update, you can head into the Steam Deck's settings menu and look for the new Security tab.
Aside from this new feature, the update brings a "refreshed" achievements page, which Valve says is now "faster to load and easier to navigate." There are localized keyboards for 21 languages and layouts, and you can enable multiple ones simultaneously. Valve says it's "currently working" on Chinese, Japanese, and Korean keyboards.
It also supports games and apps with multiple windows (like browsers or games with launchers). You can toggle between the windows by pressing the Steam button while in the game. If you want the new features, you can download the update now. You can read the full patch notes here.