Key Points

A map is a flat drawing or representation of the Earth's surface or a part of it, as seen from above. An atlas is a collection of maps in a book.

The three essential components of a map are distance (shown by a scale), direction (indicated by cardinal points), and symbols (standardized icons for features).

The four main directions are called cardinal directions: North (N), South (S), East (E), and West (W). Most maps indicate the North direction with an arrow.

A globe is a spherical model of the Earth. It is a more accurate representation than a flat map because it shows the correct shape, size, and location of continents and oceans without distortion.

Latitudes are imaginary horizontal lines that run east-west, parallel to the Equator. They measure the distance of a place north or south of the Equator and are expressed in degrees.

The Equator is the 0-degree latitude line that divides the Earth into the Northern Hemisphere and the Southern Hemisphere. It is the longest parallel of latitude.

Longitudes are imaginary vertical lines that run from the North Pole to the South Pole. These lines, called meridians, measure the distance of a place east or west of the Prime Meridian.

The Prime Meridian is the 0-degree longitude line that passes through Greenwich, England. It divides the Earth into the Eastern Hemisphere and the Western Hemisphere.

The network of intersecting parallels of latitude and meridians of longitude forms a grid on the globe. This grid system allows us to pinpoint the exact location of any place on Earth using its coordinates.

The Earth rotates 360 degrees in 24 hours, which means it covers 15 degrees of longitude every hour. This relationship is used to determine local time around the world.

Local time is the time at a particular place determined by the sun's overhead position. Standard time is the uniform time adopted by a whole country or region for convenience.

Indian Standard Time (IST) is the official time for all of India. It is set at 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT).

The world is divided into 24 time zones, each roughly 15 degrees of longitude wide. The boundaries of time zones often follow national borders to keep a uniform time within a country.

The International Date Line is an imaginary line located at approximately 180 degrees longitude, opposite the Prime Meridian. When you cross this line, the date changes by one day.

Centuries before Europe, ancient Indian astronomers used their own prime meridian called the 'madhya rekha'. It passed through the city of Ujjayini (modern Ujjain), which was a famous center for astronomy.