The Replication Factor is a strategy that is used in designing Cassandra to handle Big Data efficiently and preserving the data is a priority, and therefore, it stores data on different nodes. As any node could go down at an instant, we can use the data from a different node to get the work done.
So, a Replication Factor of 1 means, there is only a single copy of the data, and if RF is 2, it means there are 2 copies of the data. If you want to learn Cassandra, check out the Cassandra course from Intellipaat, which offers you industry-grade training and projects to help you enhance your hands-on experience. Also, to get a better head start, watch the following YouTube video on Apache Cassandra Tutorial.