Some critical I/O devices that you would need with a personal computer consist of monitor, keyboard, speakers, and mouse. You need the monitor to be able to see what you are doing. If you didn’t have a monitor it would be the same as working in the dark, or even trying to do what you need to do blind. You would need the keyboard to be able to input instructions/demands. Without a keyboard you may not be able to input instructions for the computer to do. The keyboard is a necessity for day to day use. Speakers are critical in the sense that you need to hear. Sometimes if you can’t listen to what is going on around you then you may not be able to do some of the important things that need to be done. The reason a mouse is critical is because, if you don’t have a notebook, that comes with a built in touch pad as the mouse then you need the mouse to be able to navigate from page to page, or click on items that are important. Without a mouse it would be the same as writing without a pencil or pen.
Un-necessary I/O devices that I would consider un-necessary would be a printer and a webcam. The reason that I say that a printer is un-necessary is because although it is an essential I/O device it is not something that you would need for an everyday use because of the fact that you would not need to print something every day. Due to this reason it is not considered necessary. Another un-necessary device would have to be a webcam. A web-cam is not considered necessary because it is not what is needed for an everyday use. For example would you need to see someone’s face every day? Why would you need to see someone’s face every day? For that reason it is considered un-necessary.
A modem is considered an I/O device because of the fact that it connects to a port on the computer. The modem after connection sends out information to the computer saying “hey I am a device” and then telling the computer that it is connected to internet. This being that it sends and collects data