Difference between partition key, composite key and clustering key in Cassandra?

Question

I have been reading articles around the net to understand the differences between the following key types. But it just seems hard for me to grasp. Examples will

Answer 1

In brief sense:

Partition Key is nothing but identification for a row, that identification most of the times is the single column (called Primary Key) sometimes a combination of multiple columns (called Composite Partition Key).

Cluster key is nothing but Indexing & Sorting. Cluster keys depend on few things:

1. What columns you use in where clause except primary key columns.

2. If you have very large records then on what concern I can divide the date for easy management. Example, I have data of 1million a county population records. So for easy management, I cluster data based on state and after pincode and so on.