Backend use cases

The backend part of a DQCsim simulation is what people usually mean when they talk about a quantum computer simulator: it simulates the behavior of qubits in a quantum circuit.

There are various mathematical ways to go about doing this, with their own pros and cons in terms of accuracy, simulation speed, and memory footprint. This is primarily why being able to swap out the backend is very powerful.

Another big reason for wanting to swap out backends would be to get access to different error models. However, it is strongly recommended to describe such error models in the form of a operator plugins, if it's possible to describe them by modifying or inserting additional gates.