Answer:
Clastic sedimentary rocks- When the source rocks are weathered, it breaks down into smaller particles. These broken fragments are transported from one place to another with the help of agents such as wind, water and ice. These sediments are then accumulated at another place, and after compaction and lithification, it forms clastic sedimentary rocks. The 'clast' here means the broken rock fragments. For example, Conglomerate.
Chemical sedimentary rocks- these are sedimentary rocks that are formed from the deposition of the minerals that are commonly precipitated from water or other solution. For example, Rock salt.
Organic sedimentary rock- These are sedimentary rocks that are formed from the accumulation of organic matters such as the remains of fossilized flora and fauna, which are compacted with other sediments and eventually forms this organic sedimentary rocks. For example, Oolitic limestone.
These 3 types of rocks differ from one another in terms of their composition, but they all form by the same process i.e. the compaction and lithification of sediments.