TYPES OF COMPUTER KEYBOARDS
1.Flexible Keyborads: These keyboards work just the same as standard keyboards but are meant for people on the move. They are typically made of silicon, which is water and dust-resistant and don't require constant cleaning. These keyboards are a junction between normal type and laptop type keyboards: noraml from the full arrangement of keys, and laptop from the short key distance. Additionally, the flexibility alllows the user to fold/roll the keyboard for better storage and transfer. However, for typing the keyboard must be resting on a hard surface.
2.Gaming Keyboard:Gaming keyboards are enhanced versions of standard keyboards and have many additional features and functions. Usually, these keyboards have illuminated keys to help gamers play at night. At the same time, these keyboards also consist of multimedia keys that enable users to adjust the volume; various shortcuts for multiple tasks such as check mails while playing, and palm rests to reduce the strain on the user’s hands while playing games.  
3.Projection Keyboard: This is a device that can be connected through Bluetooth to your mini PC, tablet computer or even smartphone. Projection keyboards project an image of keys, usually with a laser, onto a flat surface. The device then uses a camera or infrared sensor to "watch" where the user's fingers move, and will count a key as being pressed when it "sees" the user's finger touch the projected image. Projection keyboards can simulate a full size keyboard from a very small projector. Because the "keys" are simply projected images, they cannot be felt when pressed. Users of projected keyboards often experience increased discomfort in their fingertips because of the lack of "give" when typing.
4.Standard keyboard:Also known as "QWERTY" keyboard. These keyboards consist of a range of functions at the top of the keyboard; as well as numbers 1 to 0; a separate numeric keypad to the right; punctuation symbols, and letters A-Z that start from the “QWERTY” sequence. These keyboards are perfect for any standard use such as normal typing, day-to-day browsing, etc.  Also the enter key is usually shaped differently. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys, such as the command or Windows keys. 
5.Laptop-size Keyboards:Keyboards on laptops and notebook computers usually have a shorter travel distance for the keystroke, shorter over travel distance, and a reduced set of keys. They may not have a numeric keypad, and the function keys may be placed in locations that differ from their placement on a standard, full-sized keyboard. The switch mechanism for a laptop keyboard is more likely to be a scissor switch than a rubber dome; this is opposite the trend for full-size keyboards.

Major difference between the types of keyboards
FLEXIBLE KEYBOARD      It is being used with any type of computer because it is movable.            
GAMING KEYBOARD        It is being used with only gaming laptops.	 
PROJECTION KEYBOARD    It is being used with any type of laptop and even can be used with tablets, smart phones.It is being used with either a laptop or desktop computer.
STANDARD KEYBOARD      It is being used with either a laptop or desktop computer.
LAPTOP-SIZE KEYBOARD   It is being used with only a laptop computer.