SBo - SlackBuilds.org. The website and git repository. Also, sometimes
(incorrectly) used to mean a SlackBuild (as in "I installed the SBo
for <whatever>").

SlackBuild - hopefully this is obvious: A script (with accompanying .info
file and README) that runs on a Slackware system and creates a Slackware
package. In these HOWTOs, SlackBuild is used to specifically mean a
SlackBuilds.org SlackBuild (unless otherwise stated).

Package - Usually used to mean an installable Slackware package.
These are .tgz (or .tgz, .tlz, etc) archives with a specific
layout. Occasionally, the word "package" will be used to refer to the
source archive or the SlackBuild itself. This is confusing, so try not
to do it.

Project - whatever your build is packaging. Usually this is a program,
but it may also be shared libraries, data, or any combination of the
above.

Upstream - the author(s) and/or maintainer(s) of the project. Many
projects ship a file called AUTHORS that tells who this is. Also,
projects hosted on GitHub or GitLab have a username that
owns/publishes the project.

Tarball - an archive file, created with tar(1) and optionally
compressed. In these HOWTOs, there are two types of tarball discussed:
source tarballs (what your .info file lists as DOWNLOAD), and
submission tarballs (what you upload to the SBo site, when you use the
submission form; also, what you download from the SBo site when you
download a SlackBuild).

Maintainer - the person who's responsible for a given SlackBuild
on SBo. When a SlackBuild is first submitted, this is the author.
However, builds can change maintainership for various reasons, so the
current maintainer might not be the original author.

Orphaned - An orphaned build is one that has no maintainer. There's a whole
FAQ about orphaned builds here [link]

Tree - a copy of the SBo repository. This could have been created with
"git clone", or rsync, or recursive wget.

Mailing List - see [link]

Build System - the software used to build a Project. Examples would be: make,
autotools (aka ./configure), cmake, meson (and ninja). Most of these have
build-system-specific templates [link]

Binary Repack - A SlackBuild that simply creates a Slackware package
from precompiled binaries released by the project's upstream. Usually
(but not always), these have the suffix -bin in their SBo build names.
The "source" for a binary repack can be a tarball, a single executable
(rare), an AppImage, a package for another distro (.deb or .rpm), etc.