A man made object revolving around the earth or any other planet in a fixed orbit is known as artificial satellites. Based on their functions, satellites are classified as following:
Weather satellite : Collect the information regarding weather conditions of the weather. It records information like, temperature, wind direction, air pressure etc. and sent to the research center on the earth. Based on this information study and prediction of weather is made.
Navigational satellite : Fix the location of any place on the Earth’s surface in terms of its very precise latitude and longitude. These satellites assist the user with current live maps as well as real time traffic conditions, also assist the surface, water and air transportation and coordinate their busy schedule.
Broadcasting satellites : Broadcasting satellites are used to transmit various radio and television programmes and even live programmes from any place on the earth to any other place.
Earth observation satellites : Use of these satellites are to observe and provide the real time information about the earth. These satellites also help us to collect the information about the resources, their management, and continuous observation about a natural of natural calamities like flood and earthquake and the changes within it.
Communication satellites : These satellites establish communication between different location in the world through use of specific waves. In order to establish communication between different places on the earth through mobile phones or computer internet communication satellites are used.
Military satellites : These satellites are used to collect information for security aspects. Every sovereign country needs to keep the real time information about the borders. Satellites help to monitor all movements of neighbouring countries or enemy countries. Military satellites also help to guide the missiles effectively.
Apart from these various satellites, certain satellites for specific works or purposes are also sent in the space. E.g. India has sent and using satellite EDUSAT for educational purpose: CARTOSAT for surveys and map making.