In the 22nd century, persocoms are everywhere. They are capable of doing everything your phone and computer can do, combined. They are humanoid computers, with only a few things that visually make them different from humans. One of these things are their ears, which are usually bell shaped and contain wires and ports for connecting to other persocoms, screens, and charging. They can also be charged via solar energy, which is why many people will take a walk with their persocoms.
Persocoms are highly evolved machinery, but many people treat them as humans, loving them even marrying them at times. However, they have no iris, which according to Japanese belief, means they have no soul. Like most electronic devices, fully slumbering a persocom in water will permanently disable them. Most persocoms are left at standard, factory model specifications. Still, there are a few who are well versed in technology who will upgrade, modify, even build special persocoms. Typically, these persocoms are more human with emotions and actions than standard models.
The differences between a chobit and a regular persocom are both vast and few. The power button is located in a very specific spot for chobits, whilst it typically located in the ears on a standard model. While persocoms can imitate human emotion, to a certain degree, chobits can actually feel. Chobits have the ability to learn the way humans do, as well as downloading information. They are closer to human than machine.