The word Atmosphere refers to the layer of gases that surrounds the Earth. These gases are retained by the Earth's gravity.
Meteorology is the science, a branch of Geography, that studies the pehnomena occurring in the atmosphere. They are called meteorological phenomena.
Meteorological phenomena give rise to Weather and Climate.
While weather is the state of the atmosphere on a place at an specific moment. Climate is the average state of the atmosphere on a place during a long period of time, the weather patters over more than 30 years.