Meteorology is the study of the changes in temperature, air pressure, moisture, and wind direction in the troposphere. These two work together to form clouds, to make rain and thunderstorms, and to cause winds to blow. The sun emits energy at an almost constant rate, but a region receives more heat when the sun is higher in the sky and when there are more hours of sunlight in a day. The high sun of the Tropics makes this area much warmer than the poles, and in summer the high sun and long days make the region much warmer than in winter. The wind blows because air has weight.
Cold air weighs more than warm air, so the pressure of cold air is greater.
When the sun warms the air, the air expands, gets lighter, and rises. Cooler, heavier air blows to where the warmer and lighter air was, or in other words, wind usually blows from areas of high air pressure to areas of low pressure. A cloud occurs when the invisible water vapor in the air becomes visible water droplets or ice crystals. The water vapor becomes visible by cooling. That is what happens on a cold wintry afternoon when you see your breath.