What is MySQL Cluster vs Replication ?

What is MySQL Cluster Manager Architecture:
MySQL Cluster Manager is a distributed client/server application consisting of two main components. The MySQL Cluster Manager agent is a set of one or more agent processes that manage NDB Cluster nodes, and the MySQL Cluster Manager client provides a command-line interface to the agent’s management functions.
A Cluster is a collection of commodity components to provide scalability and availability at a low cost. It is possible to create a database cluster for high-end enterprise applications by storing and processing information on commodity nodes.

What is MySQL Replication :
Replication enables data from one MySQL database server to be copied to one or more MySQL database servers (known as replicas). Replication is asynchronous by default; replicas do not need to be connected permanently to receive updates from a source. Depending on the configuration, you can replicate all databases, selected databases, or even selected tables within a database. MySQL replication is a process that allows data in one or more MySQL database servers, called slaves, to automatically remain in sync with one master MySQL database server.

In a replication setup, a master MySQL server updates one or more dependent. Transactions are committed constantly, and a slow transaction can cause the slave to lag behind the master. This means that if the master fails, it is possible that the slave might not have recorded the last few transactions. If a transaction-safe engine such as In DB is being used, a transaction will either be complete on the slave or not applied at all, but replication does not guarantee that all data on the master and the slave will be consistent at all times.
In MySQL Cluster, all data nodes are kept in synchrony, and a transaction committed by any one data node is committed for all data nodes. In the event of a data node failure, all remaining data nodes remain in a consistent state.