I think this is referring to clients that are actively connected and transmitting / receiving data. For example, watching a video means you need a fairly constant connection to the server. 100 concurrent users would be able to begin watching a, lets say 10 minute video. For these 10 minutes, the server may not accept a new user. After 10 minutes, slots free up that can handle other users. Technically it is more complicated than this, involving bandwidth, number of cores / threads, databases, queries, etc which will limit how many users the service can handle, and connections can be made and broken to allow the service to serve a larger number of concurrent clients.
In the above example, you have 100 users every 10 minutes which is 14,400 users a day assuming 100% utilization
That is the opposite of what the we should have learned from what happened with the Nazis and what Milgram experiment warned us of. Its the reason there’s memes about “just following orders.” If pressured, most people will just listen to what theyre told even if it means knowingly hurting someone.
Passive acceptance is part of the reason Nazis were able to take over while not being the majority in Germany.