Giffgaff is a mobile virtual network operator (MVNO) in the United Kingdom that uses the O2 network for its mobile services. This means Giffgaff does not have its own physical network infrastructure but operates by utilizing the O2 network owned by Telefónica. As a result, Giffgaff customers have access to the same network coverage and speeds as O2 users, although Giffgaff offers its own plans and pricing separate from O2. Giffgaff is known for its flexible plans and community-focused approach, and it operates as an online-only brand under Virgin Media O2.