Green plants absorb light energy from the sun, and absorb water from the soil, to make their own food. This process is called photosynthesis (get used to the name, you will hear it a lot in the future!). Different types of plant are adapted to maximise the amount of light and water they absorb. They are also adapted to the temperature of the environment they live in.
Some plants like the cactus are adapted to living in hot, dry deserts.
Some plants, like these reeds, are adapted to living in ponds and small waterways.
Over long periods of time, adaptations which are very successful and help individual plants to thrive become common in almost all plants of that particular species. This process is known as evolution.
Some trees have evolved to live in hot, wet places, creating rain forests. Other trees grow in climates which change across the year, from cold winters to hot summers.