Right-of-way (ROW) can be defined in a variety of ways, but in general land terms, it is the legal right, established by usage or grant, to pass along a specific route through grounds or property belonging to another.
A right-of-way allows local and state governments to construct and maintain roads, stormwater systems and sidewalks to facilitate pedestrian and vehicular movement. ROWs are also used by the utility companies (Gas, Electric, Water, Sewer, Cable, Fiber Optic etc.), to install and maintain their utilities.
Often a plat or survey will show the property line up to the ROW that is managed by the government. (Note: An exception to this is when the ROW is a permanent easement. In this case, the government has permanent and perpetual access to the property in the easement, but the property owner still retains legal ownership to the entirety of the parcel. There is little practical difference between these two types of ROWs. The distinction is a legal one.)