the vertical section through different layers of soil is called soil profile. Each layer of the soil has different composition of minerals,amount of sand,etc.
1)the firsst layer is the topsoil or the A-horizon where all small plants are rooted.this layer is also very rich in humus and minerals which, again helps in growth of plants.
2)The second layer is called B horizon. this the middle layer which consists of less humus but more of minerals.
3)The third layer is the C-horizon which has small lumps of rocks with cracks and crevices. Below this is the bedrock, which is hard and difficult to dig with a spade.