The snipping tool on Mac works similarly to the snipping tool on Windows PC with some differences. Mainly, it is used via a keyboard shortcut (no print screen button on Macs 🥲). And to annotate screenshots, you have to open a separate application (Preview).
The Mac screen capture tool is accessible via a keyboard shortcut command or by searching Spotlight for 'screenshot.' The screen capture options panel is accessible by the Commmand+Shift+5 command.
You can also use Command+Shift+3 to capture a portion of the screen, Command+Shift+Ctrl+4 to copy screenshot to clipboard or Command+Shift+3 to take a fullscreen screenshot. More on Mac screenshot keyboard shortcuts here.
After pressing Command+Shift+5 keyboard shortcut on your Mac, a screen capture menu with options to capture a portion of your screen either via a screenshot or screen recording will show below onyour screen (example shown is on MacOS Big Sur):
As mentioned above, there are also direct keyboard shortcuts on the mac to screen capture to clipboard, screen capture visible window..etc. that you can checkout here — 3 quick keyboard shortcuts to take a screenshot on mac.
After saving your screenshot to your Mac desktop, find the image file and open it in Preview.
Or if you can catch it, there is a small mini preview window that pops up on the bottom right of your mac's screen. Clicking on it will open the image in Mac Preview with annotation mode enabled.
You can then draw, add shapes, text..etc to annotate it. Click 'done' to then save your screenshot with annotation to a directory on your computer.