The term LOCI is a four letter word which refers to collections of points in mathematics. It is derived from the Latin word for 'PLACE' and is used to describe a set of points that satisfy a given set of conditions. In geometry, LOCI are used to describe the position of points on a line, circle, or other shape. In algebra, LOCI are used to describe the solutions of equations. In calculus, LOCI are used to describe the paths of curves. In all cases, LOCI are used to describe the relationships between points in a mathematical system.