# Managing Clusters: Adding/Removing Nodes
The `Raft` type offers various API methods to control a raft cluster.
Several concepts are associated with cluster management:
- `Voter`: A raft node responsible for voting, electing itself as a `Candidate`, and becoming a `Leader` or `Follower`.
- `Candidate`: A node attempting to elect itself as the Leader.
- `Leader`: The sole node in a cluster that handles application requests.
- `Follower`: A node that acknowledges the presence of a valid leader and only receives replicated logs.
- `Learner`: A node that cannot vote but only receives logs.
`Voter` state transition:
```text
vote granted by a quorum
.--> Candidate ----------------------> Leader
| v |
'----Follower <--------------------------'
```