Performance & battery · When your Mac feels slow
Is running low on memory the same as running low on storage?
Short answer: No. Memory is short-term working space for open apps; storage is where files live. Freeing storage won't add RAM, but macOS uses free disk as virtual memory, so a nearly full disk makes memory pressure worse.
No. Memory (RAM) is short-term working space for the apps you have open; storage is the disk where your files and apps live. Freeing storage doesn't add RAM, and Storage Studio doesn't "clean" memory.
They are connected, though: when memory gets tight, macOS uses free disk space as virtual memory, so a nearly full disk makes memory pressure feel worse. Closing a few heavy apps is the quickest relief for memory pressure.
Ask Tuhi "Why is my Mac low on memory?" and it will read your current memory use and tell you whether it's actually tight right now. See also Does a full startup disk slow a Mac? and Freeing space.