Devices and simultaneous connections
A pass allows 4 connections at once, from any devices and networks. The free trial allows 2 per IP address.
Each file you download or stream from a device uses one connection. Players and download managers open several requests per file, to seek or to go faster: up to 16 on the same file from the same device count as that one connection.
With a pass
Up to 4 connections at the same time, from any devices and any networks: your TV and your laptop at once, a VPN, mobile data. There's no single-IP rule. A pass is for you and your household: reselling access or publishing your links isn't allowed.
On the free trial
Up to 2 connections at once per IP address.
Over the limit
An extra connection is refused (error 429 in a download manager) until another one ends. Keep the number of files downloading at once within your limit: see Download managers.
Signed in everywhere
Sign in on as many devices as you like. Security lists them and lets you sign any of them out.