For challenges involving a grid.
Grids (ie lattice paths) are a way of organizing data into rows and columns, like unto a spreadsheet. This challenge either requires output in the form of a grid, input in the form of a grid, or otherwise expects you to use a grid in some way.
This tag can also be used for KotHs involving movement on a grid.
There are multiple types of grids. The most popular is the square grid, where each point corresponds to a coordinate of integers and each point is connected to those other points with a coordinate differing by 1.
There are other grids however including Hexagonal and Triangular tilings of the plane.