Why there are 5 Versions of Timer Classes in .NET?

Question

Why are there five timer classes in the .Net framework, namely the following:

1. System.Timers.Timer
2. System.Threading.Timer

Answer 1

Timers.Timer generates an event after a set interval, with an option to generate recurring events. MSDN

Windows.Forms.Timer is a Control for winforms.

Web.UI.Timer performs asynchronous or synchronous Web page postbacks at a defined interval. MSDN

Threading.Timer is the timer for Callbacks. Creates a new Thread for working. Served by thread pool threads. MSDN

So, these timers have different purposes, also they are served by different tools.