When we talk about climate, we mean that somewhere is normally warm or cold, dry or humid. The climate of an area is the way it has been observed over years. So you think of a long period of time. The weather is something similar, but you talk about the weather when you think about a day or a few weeks. So weather is about a short period of time.
The climate depends very much on the proximity to the equator. It is hotter near the equator and colder towards the North Pole or the South Pole. Europe lies roughly in the middle. That's why most countries here have a temperate climate. So it usually doesn't get very cold or very warm, except in many areas south of the Alps.
On the other hand, it is hot in the areas around the equator, for example in Africa and South America. This area is called the tropics. It can be hot and humid, and you often find rainforest there. If it is dry and hot, you will find desert.
The climate can change, but it usually takes many years. Humans also contribute to changing the world's climate. This climate change comes about because factories, cars, aeroplanes, heaters and livestock in particular emit gases, for example carbon dioxide. Such gases cause certain parts of the sun's rays to heat the earth more.