Weather is the daily and weekly change in temperature, humidity, rainfall, snow, wind and sunshine. Weather is what you feel and see as you go about your daily life.
The climate of a place is the typical pattern of weather that occurs across a year or over several years.
The climate of California is dry.
The climate of Hong Kong is humid.
The climate of Iceland is cold.
When weather patterns change over ten to fifty years or more, we can say that the climate has changed, e.g. “California has become wetter” or “The UK has become stormier”.
Recording daily weather and keeping records over decades or even hundreds of years is vital to detect and track changes in climate.
"Global warming" refers to the long-term warming of the planet.
Different parts of the world have different temperatures, but it is possible to take an average of these and define a global average temperature. The global average temperature of the Earth has gone up and down over the whole of the planet’s history as a result of natural forces. When we talk about “global warming” today, we mean the observed change in the global average temperature since the start of the industrial revolution. Global temperature shows a well-documented rise since the early 20th century and most notably since the late 1970s.
This is the observed and predicted changes in long-term weather patterns (the climate) that have happened because the Earth’s global average temperature has increased.
These include rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times.
These are all consequences of the warming, which is caused mainly by people burning fossil fuels and putting out heat-trapping gases into the air. The terms "global warming" and "climate change" are sometimes used interchangeably, but strictly they refer to slightly different things.
"Global Heating" has recently been suggested as a more accurate way to describe this phenomenon and may be a phrase that you hear in the future.