Comm-links are your personal portal to the matrix. They allow you to experience the Matrix through Virtual Reality (VR) or Augmented Reality (AR).
Commlinks can also be used to access the matrix much like a modern day phone accessing the internet, through the screen/controls on the device itself.
AR lets you experience the Matrix as an overlay on the physical world. Nodes physically close to you will project AR imagery to the visual receiver of your comm-link. To experience the matrix like this you require an Imagelink linking your commlink to an imaging device (like glasses or goggles). An example of this in action; you are walking down the street, your comm-link imaglinked to your glasses, you pass a restaurant and it’s menu is projected onto the outside wall. You take your glass off, and the menu will disappear. Putting your glasses back on, you decide you want to order something from the restaurant, you COULD use the buttons on your comm-link (looking like some one from a 2005 trideo) or you could use AR gloves which allow you to simply “touch” the AR overlay on the wall. Once this happens the restaurants node hooks up with your comm-link and your bank account details are exchanged, 10 Nuyen goes out of your account and a message pops up in your field of view letting you know your meal will be ready in 15. AR Matrix is ubiquitous in developed cities, but you require the appropriate devices to experience it.
VR lets experience the matrix completely “disconnected” from the physical world. Using a sim module, with either trodes or a simrig users jump in to the matrix with all of their conscious mind, the physical world ceases to exists and the matrix immerses all of the users senses. Once in the user “logs on” to the home node of their comm-link, which can be “sculpted” to appear as a city, a room, a forest, a castle, anything the user likes and can either purchase or program. The user becomes their programmed persona, which can be purchased/programmed to look like anything they choose. In VR matrix all programs, files, etc become “Icons” that can be “sculpted” to look like anything imaginable. An example; You log onto your comm-links home node in VR. You become a floating octopus, in an underwater scene. You decide you want take-away so use your load your Browse program (which appears as starfish) to Datasearch for nearby restaurants. The information from the search flashes in front of you. You find a Chinese restaurant nearby and log on to it’s node. It is sculpted as an ancient temple on top of a mountain, an elderly man asks to take your order (He is in fact an agent [semi-autonomous program] of the node). You let him know what you want and the money is taken out of your comm-link bank account. He lets you know it will be ready in 15. You Log Off and return to the squalid reality of your filthy apartment, dreading the fact you have to walk down the street to actually get the food.