How you save an image in Paint decides how well it works everywhere else — a wrong format choice is a common beginner mistake.
| Format | Best for |
|---|---|
| PNG | Sharp edges, supports transparency — screenshots, logos, diagrams |
| JPG | Smaller file size, no transparency — photos |
| BMP | Uncompressed, large file size — rarely needed today |
Ctrl+S saves over the same file. Save As (Ctrl+Shift+S) lets you pick a new name, location, or format — use Save As whenever you want to keep an original untouched.
Connects back to File and Folder Basics
Choosing the right extension here is exactly the "File Extensions" idea from Computer Basics — the file extension tells every other program what kind of data is inside.
A photo saved at its full camera resolution can be several MB — fine for storage, but far larger than any screen needs to display it, and slow to attach or upload. Resizing an image down to roughly its actual display size before saving (Image → Resize) keeps the file small without any visible quality loss.