Air flows form areas of higher pressure to areas of lower pressure. Differences in air pressure are caused by uneven heating of the Earth's surface. The land heats and cools more rapidly than does the sea. Water retains heat longer than land, and also takes longer to heat and cool. During the day , the land gets hotter faster, and the hot air rises, creating an area of lower pressure.
Wind blows from the sea to the land.
This is a sea breeze . At night , the land cools off faster than the sea. Cooler air descends creating an area of higher pressure. Wind blows from the land to the sea. This is a land breeze .