No, not you. You're not allowed
Open source home theatre sums it up pretty well
Kodi started maybe 15 years or so as the XBox Media Centre. In your Googleing you may have run across the acronym XBMC
Back in the day everybody downloaded movies, pictures, and music to their PCs and laptops. Getting the content from your PC or laptop to your TV could be a challange so Microsoft came up with the idea of a centralized media centre. First with the short lived Windows Media Centre then as part of their gaming platform on the original XBox and onto the XBox360. The idea being your media is shared from your Windows based computer onto your home network and made available to your TV via the XBox
XBMC never really took off and the project was abandoned and Open Sourced. From there the Linux community took over and began the evolution from XBMC to Kodi.
Media could be stored on the computer that XBMC (later renamed Kodi) was running on, shared on your local network, or even on a remote server somewhere. Media could then be played back on your big screen TV via the Kodi interface
Then came The Cloud. Now you can watch TV on the internet. Go to your favorite TV network's website and get a live stream. Watch ESPN online. HBO. Porn sites. Video feeds everywhere
Instead of hooking up a laptop to your TV and watching it thru a web browser, Kodi provides a platform that centralizes your local media, shared media, remote media, and streams from the cloud
There are several official Kodi add ons to watch publicly available TV shows, movies, and live streams. Since Kodi is Open Source there are also a large number of "unofficial" add ons as well that tap into non-publicly available streams and media sources
These unofficial addons are what has made Kodi so popular the last few years
Kodi is available on Android, Apple IOS, Linux, Windows, Raspberry Pi, and I think the Mac fanboys have a port as well. Amazon FireTV/Firestick is a derivative of Android TV however it is not available on the Amazon app store. That said it is possible to install on FireTV/Firestick via a process known as sideloading. Unfortunately Kodi is not available on a Roku.