Degrees - the unit for measuring distance on a map projection. The actual distance can vary somewhat. Since lines of longitude come together at the poles, the distance covered by each degree shrinks. However, as lines of latitude at about the same distance apart, 1 degree of latitude varies only slightly. 1 degree of latitude is about 111 km.

Equator - the equator is an imaginary line separating the northern and southern hemispheres. The equator is exactly half way between the north and south poles. It runs the circumference of the Earth and is the longest distance around the planet.

Globe - a globe is a miniature model or representation of the Earth. It has the same shape as the Earth and usually has a cover that shows the various surfaces and elevations of the planet. Seas and oceans are shades of blue/green. Mountain ranges are often coloured shades of brown. Some globes show the borders between countries and boundaries between provinces and states.

Hemisphere - one half of the planet. Maps divide the Earth into 2 halves. The hemispheres are divided along the equator or the Prime Meridian. Divided at the equator makes a break into north/south. Divided at the Prime Meridian makes a break into east/west.

Latitude - the horizontal lines one a map that mark the distance north or south of the equator

Longitude - the vertical lines on a map that mark the distance east and west of the Prime Meridian.

Map Projection - any map that attempts to take the spherical (ball) shape of the Earth and represent it as a flat image. All atlases and paper maps do this.

Meridian - vertical lines on a map that extend from one pole to the other. There are often referred to as lines of longitude.

Prime Meridian - the meridian that is the starting point for measuring distances to the east or west. The Prime Meridian is at 0 degrees and runs through the city (among others) of Greenwich, England.