Rights of way are paths and tracks which you can use to cross private land. If a member of public strays off a right of way onto land which they have no other rights of public access they will be committing a trespass against the landowner.
There are four types of path on which you are allowed to do different things. Look out for waymarks for guidance.
It is a criminal offence to prevent the public exercising these rights.
Walkers and Mobility vehicles
A footpath is a highway over which the public has a right of way on foot only.
A bridleway is a highway over which the public has a right of way on foot, horseback and on a pedal cycle (including mountain-bikes).
There may also be a right to drive animals along a bridleway
A restricted byway is a highway over which the public is entitled to travel on foot, horseback and with non-mechanically propelled vehicles (such as pedal cycles and horsedrawn vehicles).
There may also be a right to drive animals along a restricted byway.
A Byway Open to All Traffic (BOAT) is a highway over which the public is entitled to travel on foot, horseback or pedal cycle and by wheeled vehicle of all kinds, including horse-drawn vehicles, but which is used by the public mainly for walking or for riding.
Most of these highways do not have a surface suitable for ordinary motor traffic.