windows snip shortcut for linux code example

Example 1: is there a snipping tool on ubuntu

No need for it if you have a quick and easy shortcut:
Shift + PrtScr

Select the area.
screenshot is saved in Pictures folder.

Example 2: particular screenshot in ubuntu

Prt Scrn to take a screenshot of the desktop.
Alt + Prt Scrn to take a screenshot of a window.
Shift + Prt Scrn to take a screenshot of an area you select.