Scareware is usually found in websites, the user may find them in forms such as 'Your computer is infected with a virus, please call immediately!' However, these are not true, as they are mostly designed to scam people.
Online scareware is the most common form of scareware. They can be accessed from suspicious websites that redirect the page. Many are known as browser hijackers. Browser hijackers are websites that lock the user's browser, preventing them from closing out of it, however, those can easily be fixed by going to the task manager. An example of an online scareware is Microsoft Official Support.
Rogue Software is a fraud software that may scam people out of their money. Some ways can be rogue antiviruses, which warns the user of nonexistent malware and encourages the user to buy their 'premium' version. This can be considered scareware because they may scare the user into another scam.