LineageOS and /e/ have been developing their own Recoveries. They both seem to be based on TWRP, they are simplified and they are device specific. For LineageOS and /e/ this has the effect that documentation is simpler to write, per device, when describing the install process. The /e/ system (advanced) is also capable of keeping the /e/ Recovery updated.
Many experienced users prefer TWRP because of other opportunities offered within the Recovery mode. (Documentation written before /e/ Recovery was mainstream simply does not mention it!)
For a user with zero experience of TWRP, following /e/ Recovery instructions should be a little more intuitive, as the /e/ Recovery allows very few options.
Some documentation tends to prefer Linux methods. Heimdall is a Linux product.
It is said that Odin is a semi-official Samsung product released to Windows.
Heimdall is developed in Linux - now available in a Windows version!! Choose to use Windows or Linux according to your PC operating system. Read all you can for the broadest overview, but once started please only follow one set of instructions. 