Which of the following best describes what Web 2.0 is?

A) Is not available to use 24/7.
B) A one-way communication device.
C) Does not allow people to communicate through the internet.
D) Is never accessed on smartphones.
E) A communication device for users and senders.

Web 2.0 is a communication platform that allows users to communicate and interact with each other through the internet. It enables two-way communication and allows users to create, share and collaborate on content. It is accessible on various devices, including smartphones.