Computer users, rough speaking, fall into one of several categories. Here is a brief summary.
Extreme users spend nearly every waking moment in front of a computer and do so voluntarily. These folks are completely techno enthusiasts. They tend to be attracted to such things as web design, gaming, programming, computer graphics, etc. They use the computer as a tool and as a form of recreation. Their lives are intertwined with the internet. These are people who would be lost without a computer. They always want to have the latest and fastest computer and are willing to pay top-dollar for it.
Heavy computer users are individuals who tend to use computers for a work-related purpose. This alone consigns them to life in front of a computer screen. They spend around a 3rd of their lives in front of a computer. They tend to become adept at using various applications. They tend to develop decent typing skills out of sheer repetition. Heavy computer users are not necessarily techno enthusiasts, although they can be.
Moderate computer users tend to use computers for a variety of everyday tasks, such as finding movie reviews, checking account balances, email, word processing and so on. The people who are not afraid of technology, but at the same time, not techno enthusiasts. Computers are much like any other appliance – something to be used to accomplish a particular task, or even for general enjoyment. Web browsing is probably the most popular activity for moderate computer users. They posses a basic level of computer knowledge.
Most casual computer users tend to use computers infrequently. It's not uncommon for many casual users to have spent most of their lives in the pre-computer era – ie, pre-1980's. Many of these folks simply do not appreciate the need for a computer since they have sent a major of their lives without one. They tend to use them only when necessary, for example communicating with children and grand children. They tend to be technophobes who do not adapt to technology easily. Having a computer with the latest and fastest processor is not important to them. They are fine with using cheap used laptops and even antiquated systems like desktop units with Pentium II chips. These are not the kind of individuals you'll find in the computer section of Best Buy.