Hardware are the physical components which can be seen or touched and one can work with it.
Example: Monitor, CPU, Keyboard, Mouse.
Memory units: USB, Hard drive, CD, DVD, RAM, ROM etc.
Internal Components: Motherboard, Processor, etc.
Note: Without Hardware we cannot store any Software.
Monitor- There are majorly two types of monitors as 1. CRT and 2.Flat Panel
CRT(Cathode Ray Tube) monitors were old technology monitors which works as cathode tube bumbards light of 7 colors on glass and produces color. But these were bulky screens so no one uses nowadays.
On other hand devices became thin so for thin we find Flat Panel displays categories as LCD (Liquid Crystal Display) or LED(Light Emitting Diode).