In the U3A movement, 'Network' is a generic term for groups of U3As which have chosen to work together for the support and mutual benefit of the members of the U3As concerned.
Boundaries vary with local practice and are determined by the Network member U3As, so they may or may not follow local authority boundaries. Also, Networks may cross regional boundaries.
Networks choose their own organisational structures. Some are 'informal', with no constitution or no procedural rules, no committee or no bank account. Others may prefer to have a constitution which governs the running of the Network (eg elections to a committee, frequency of meetings, banking arrangements).
Wooler U3A is a member of the informal North Northumberland Network (for Alnwick, Berwick, Coquetdale and Wooler U3As) and of the formal Network, Northumbria Region U3A (for more than fifty U3As in the North East and North Yorkshire).
Currently, National U3A (The Third Age Trust) organises two Network Link meetings each year (in May and October) when representatives from all informal and formal Networks in the U3A movement can get together and discuss issues of mutual interest and concern.