Streaming Services will sometimes refer to the “number of streams” or “number of screens” they allow.
This refers to the number of devices that can view the streaming service at the same time. For example, Netflix has “3 concurrent screens”. That means that 3 people on the same account can be watching Netflix at the same time on different TVs (or phones, tablets, computers, anything with a screen).
If one person is watching Netflix and someone else is watching Sling TV, that doesn’t count. They have to be using the same service for the “number of screens” to come into effect.
When choosing a streaming service, if you have multiple TV watchers in your house you want to make sure you can all watch at the same time without issues.