The Wire is an omnipresent wireless network that links everything on Earth with a computer chip - which means almost everything, from mobile phones to smart fridges to traffic lights. It is essentially an environment of constant communication, integration and exchange of information. The Wire is monitored by the EYE, and a lot of money can be made on the black market by severing or shielding objects from the Wire, especially mobile phones. The Wire also functions like the Internet it evolved from, playing host to news feeds like The Hand That Bites.
Recently, the Wire has been disrupted by a phenomenon called the Static, which interrupts the signal with random data. Effects range from being a nuisance - Zoë Castillo overhears a conversation blaming the Static for a smart fridge allowing milk to go sour - to causing deadly air or ground traffic accidents, or disrupting hospital equipment.
As Zoë later learns, this Static is caused by the presence of Faith, whose residual personality remains on the Wire. However, according to Zoë, since the Collapse, neural interfacing with the Wire - which Burns Flipper apparently used to do - has become impossible. This may just apply to the physical interface for humans, though, because organic computers like Eingana, who presumably have a nervous system, appear to connect with the Wire with no trouble.