Graph paper, also known as coordinate paper, grid paper, or squared paper, is a type of writing paper with small lines that form a regular grid. It is used to plot coordinates on maps and globes, to mark zones in home planning projects, and to compose musical charts. There are two types of graph paper: linear and radial. Linear graph paper is organized into rows and columns of equal-width squares or rectangles. Radial graph paper has circles or arcs instead of squares or rectangles. Both types can be divided into smaller scales for more precise work. The number of horizontal and vertical lines on a graph paper map or globe case determines which type of graph paper it is. For example, if there are more horizontal than vertical lines, then this is called "land" graph paper and it will have many little boxes into which you can divide up your plan. If there are about an even number of lines, then this is called "sea" graph paper and it will also be divided into little boxes, but these boxes are regions on a map or globe. In reality, all land maps are sea maps and all sea maps are land maps. The difference is just how much detail they contain.