Off-the-grid or off-grid is a characteristic of buildings and a lifestyle designed in an independent manner without reliance on one or more public utilities. The term "off-the-grid" traditionally refers to not being connected to the electrical grid, but can also include other utilities like water, gas, and sewer systems, and can scale from residential homes to small communities. Off-the-grid living allows for buildings and people to be self-sufficient, which is advantageous in isolated locations where normal utilities cannot reach and is attractive to those who want to reduce environmental impact and cost of living. Generally, an off-grid building must be able to supply energy and potable water for itself, as well as manage food, waste and wastewater.

Off grid can also be applied to electrical and computer communications and networking. One popular method for off grid communication is sneakernet

Further Resources:
Off the Grid by 100 Rabbits
Secure Scuttlebutt