It's any piece of hardware that turns your TV into something that can run a player app and pull a live channel line from the internet. That covers plug-in sticks such as Firestick, small boxes running Android TV, smart TVs with the app built in on platforms like LG, and dedicated set-top boxes such as MAG, TVIP, or TiVo Stream 4K. None of them store channels themselves; they all just run software that reads a line you already own and turns it into a picture. The device you already own for another purpose, a smart TV or a game console with app support, is often enough, so the first question is what you have rather than what to buy.

Yes, the same player apps that run on a stick or box also run on Android and iOS phones, so you don't need dedicated hardware to try a service. A phone works for testing a line or watching on the go, but casting to a TV usually needs a tool like Web Video Caster or a device that supports screen mirroring. For regular living-room viewing, a stick or box gives a steadier, full-screen result than mirroring from a phone, since the phone's screen has to stay on and its own connection has to hold up for the whole session.

Barely, once it can decode 4K at all. What actually decides picture quality is your connection holding 15-25 Mbps steady for 4K or 5-8 Mbps for 1080p, since a top-tier box fed a weak line still stutters. HEVC-encoded streams run at roughly half the bitrate of older H.264 streams for the same picture, so a device and app that support HEVC stretch a modest connection further than one that doesn't. Where a device does matter is decode power for 4K itself; an older phone or budget box can struggle even when the connection is fine.

Player apps on sticks, boxes, and smart TVs take a username, password, and server address, or a single M3U playlist link, typed into an add-playlist screen. Set-top boxes like MAG or TVIP instead log in by MAC address, a fixed identifier printed on the box, so the account is tied to that specific hardware rather than a password you type in. Neither method is more secure than the other; they're just different ways of tying one account to one device. If you switch from one type of device to another, expect to set the account up again rather than reuse the exact same login.

That depends on the plan's simultaneous-connection limit, typically 1 to 5 streams at once, not the number of devices you've installed the app on. Installs themselves are unlimited on most plans, you can put the app on a Firestick, a phone, and a smart TV, but only as many of them can stream at the same moment as your plan allows. Trying to exceed that limit usually logs out the oldest active session, so check that number against how many people in your household actually watch at the same time before picking a plan.