Samsung
Clear RAM on Samsung Phones auf Samsung
Background apps are the usual reason a Samsung phone slows down over time. Each app you open stays partly active in RAM even after you switch away, and once too many processes queue up, the system has less free memory for whatever you are using right now.
One UI includes a memory manager under device care that handles this automatically in the background. That automatic process runs on its own schedule, though, so it does not always react fast enough if you just installed several apps or ran something memory-heavy like a game or video editor.
To clear RAM manually, go to Settings ➔ Battery and device care ➔ Memory ➔ Clean now. This closes background apps that are not actively needed and frees up working memory immediately.
Manual clean-up helps right after a slowdown, but it is not a fix for constant lag. If your phone stays slow again within minutes, the cause is usually storage running low or one specific app misbehaving in the background, not RAM alone.
Closing background apps this way does not delete any app data or logged-in sessions. Apps simply reload when you open them again, which can take a second longer than usual the first time.