Is it necessary for users to be online to see each other's presence status?

For users to see each other's presence status in a communication platform, it is indeed necessary for both users to be online. This requirement ensures that the presence information is updated in real-time, allowing users to know if their contacts are available, busy, or offline.

When both users are online, their status can be communicated effectively through the server, enabling a dynamic overview of presence. If one or both users are offline, then the presence information may not be current or available, as the system cannot communicate status updates effectively in such cases.

The other options do not align with how presence statuses function. For example, if only one user needs to be online, it would imply that presence information could be accessed even when the other user is offline, which is not the case for most systems that rely on real-time presence interactions. Therefore, both users being online is a fundamental aspect of presence status visibility in these platforms.