You can capture part or all of your PC screen, add notes, save the snip, or email it right from the Snipping Tool window.
To open the Snipping Tool:
Once the snipping tool is opened, you can draw a box over the area of your screen you want to capture. Once you have selected the area of your screen you wish to capture, a window will pop up where you can save your snip or draw on it for notes.
Hold Command+Shift+4 and select the area of the screen you wish to capture. All screenshots will be saved to the desktop by default.