What is Deployment and how does it differ from ReplicaSet?

Deployment in Kubernetes is an object that manages the creation and updating of a ReplicaSet, which in turn manages a set of pods. Deployment provides declarative updates for applications, allowing easy scaling, version rollback, and lifecycle management.

ReplicaSet is an object responsible for maintaining a specified number of identical pods in the cluster. It ensures that the desired number of pods is always running.

Main differences:

• Deployment manages ReplicaSet and offers additional capabilities for updates and rollbacks.
• ReplicaSet simply maintains the required number of pods and does not handle updates independently.

Example: when updating an application, you create a new Deployment with a new version, which creates a new ReplicaSet and gradually replaces the old pods.