reading "Build Files Exist" seems to suggest the package already exists, but it's not, I think.
So what is "CleanBuild" and what do the options mean: [N]one [A]ll [Ab]ort [I]nstalled [No]t Installed
And is meant by (1 2 3, 1-3, ^4) ?
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
No. On your screenshot you can see that the apps that you are trying to install are numbered. It's hard to notice because you are only installing on app so the numbering stops at one, but if you tried to install multiple apps or the app depended on an other package from the AUR you would see more entries in this list and each entry would be numbered.
So specifying a range would mean package 1, 2 and 3. An option like that can come in handy when performing updates