Peripherals are the gear that connects to your computer to make it more useable.
The range of peripherals connect to the computer by USB, Bluetooth, WiFi, or networked. These can be something as basic as a printer, and external CD/DVD drive, speakers, keyboard or mouse..
More commonly required on computer systems are the keyboard and mouse combinations. Again here there are many variations according to functions required.
These can be either USB connected, Bluetooth or wireless types. USB mice and keyboards are generally called corded because they connect by a cable to the PC.
Bluetooth devices are more likely on laptops which have the capability of using bluetooth for this purpose, though the range is generally quite limited.
Wireless keyboard and mouse combos normally have a small USB adapter that is specific to those devices and is the most common sort of cordless peripheral.
Of the brands available some specialise in key markets like gaming, graphics, etc, whilst others are general and look much like corded types.
Speakers are available to connect to your computer either by the specific sound ports, or by USB.
The USB connections are usually of lesser quality but simpler to adjust so ideal for generic home usage.
If you need top quality sound, especially for fine music, then adding a sound card and high quality speakers is the way to go. The range in quality output and speaker styles is huge, the top units costing many hundreds of dollars.
A UPS is not often thought of as a peripheral but adding it to your computer set up can help provide a longer life for the system as well as protecting you against power outages.
Many people think that its main function is to protect against power outages but I see it has most benefit in providing a steady reliable voltage input to your system, regardless of the fluctuations in power from the grid.
The lower voltages (drops in power) and then jumps back to normal will over time cause damage to all electronic components. These brownouts are part of the network operation that providers have difficulty managing as demand can vary minute to minute. The UPS is your insurance (protection) against this.
Printers are the most likely thing you think of as a peripheral and they vary enormously in type, size and function.
Common Printer types are Inkjet (Bubblejet), Laser or thermal.
Inkjets are the most common home printers, they are cheaper to run in this situation, quick to start up and produce excellent quality.
Laser printers are more common in workplaces where larger volumes in print runs are more likely. Cost per print this way is much more economical but they are more expensive to run in a home environment because of the startup requirements (power and waste toner)
Thermal printers are mostly used in the workplace when attached to a POS system to produce receipts, etc. They used to be used for fax machines but these are less common now.