Tuflow and estry manual Version 3

polyline (or Pline)
A GIS object representing one or more lines connected together. A polyline has a length but no area.
polyline segment	One of the lines that make up a polyline.
region	A GIS object representing an enclosed area, ie. a polygon. A region has a centroid, perimeter and area.
SMS	Surface Water Modelling Software distributed by BOSS international for viewing TUFLOW results.
snap	When geographic objects are connected exactly at a point or along a side. For example, use the “snap” feature in MapInfo. The snap tolerance can be changed using Snap Tolerance.
u-point	Computational point, midway along the right hand side of a 2D cell, where the velocity in the X-direction is calculated. The cell’s left hand side also has a u-point belonging to the neighbouring cell to the left.
v-point	Computational point, midway along the top side of a 2D cell, where the velocity in the Y-direction is calculated. The cell’s bottom side also has a v-point belonging to the neighbouring cell to the bottom.