The matrix can be closely compared to the world wide web of our time. The differences between our internet and the AE matrix lie mainly in its scope and in the scale of its immersion. Whereas people today connect to and look at the internet from the outside, people in AE's timeline connect and view the matrix from the inside. Not all uses of the matrix necessitate this complete immersion, however. Most if not all devices such as datapads, holovids, and digital book readers are assumed to be capable of connecting to and making use of the matrix externally. Communicators and their auto-translators make use of the same connections, as do ship StarNav systems and countless other vital components that help to maintain some semblance of a functional society. Devices are, for the most part, linked to the matrix in the same way humans can be, and can be used to access corners of it without decking in completely.
Occupying a personae to connect to the matrix fully is about as common as using a Reddit or Facebook account is in our time. Some use it constantly, some only on rare occasion. The majority dabble without making it a lifestyle. The dedicated few who do make it their lifestyle are dubbed deckers or slicers, depending on who you're talking to. They don't dabble or dip their toes into the matrix, they know the tricks to wield it and can manipulate it to do their bidding.
In short, it would be strange to find a person who doesn't deck in at least occasionally, be it for online shopping or to catch up with friends. Highly dedicated and skilled users are deckers, and they are much less common.
The scope of the matrix vs. the internet is also worth touching on, as the increased scope of the former was the most significant motivator behind its development. The internet was officially "retired" in 2052, by which time it was already a tired and clunky dinosaur struggling to accomplish all of what humanity needed it to. The launch of the matrix was revolutionary for many reasons, but at the forefront of its achievements lay the ease with which it stabilized the literal and figurative connections used by mankind; from one edge of the Solar System to the other, communication became quick, easy, and smooth. Signal strength and dead sectors became a thing of the past. Whereas the internet required wires, routers, and a certain proximity to some physical source, the matrix is simply everywhere.