what is the relationship between pressure and wind?
As answered previously...
Remember that wind blows from an area of high pressure to low pressure regions. When a place (land areas) gets heated up (in summers) the air around it gets heated as well. Hotter air being lighter than cooler air, it moves upwards and creates a region of low pressure in its place. The cold air which is not at a higher pressure now reaches the low pressure areas and we experience it as a light breeze or wind. This is what is basically explained regarding the diagrams regarding monsoons. It is always cooler air that is flowing from one place to another causing monsoons etc.