[Android Central Question]

And do u have to be where your Wi-Fi router is in order to use direct connect

[SpookDroid]

A hotspot is basically a phone/device sharing it's connection via WiFi (acting as a WiFi router), so yeah, your Tab S3 is perfectly capable of connecting to a hotspot, provided you have the right credentials to connect to it.

WiFi Direct, however, is a different thing. That's a direct connection between two devices (peer to peer), so no need for a WiFi router 'in the middle'; that's the point of WiFi Direct. You use this to share files quickly or, in some cases, to use the faster transfer speed of a direct WiFi connection to mirror or share content.