Which of the following is an essential concept related to Cloud?Group of answer choicesReliabilityAbstractionProductivityAll of the above

All of the above. Cloud computing is associated with all three concepts:

1. Reliability: Cloud services are often set up to be redundant, meaning that if one server or center fails, another can take over. This makes them highly reliable.

2. Abstraction: Cloud computing abstracts the complexity of underlying infrastructure management to the users. Users can access and use the services without worrying about the technical details of how they are implemented.

3. Productivity: By using cloud services, businesses can increase their productivity. They can access their data and applications from anywhere, at any time, and they don't have to worry about maintaining their own servers or infrastructure.