A desktop publishing application from Microsoft that focuses on page layout and graphic design.
I'm sorry to say this but Microsoft Publisher has always been the most awful, horrible piece of rubbish. Word is much better. Most people who actually know anything about design or publishing detest Publisher.
Publisher was designed in the bad old days of Microsoft to try to lock people in to a format that nothing else understands (except recently Libre Office) in order to play monopolist and try to cut out the likes of Adobe InDesign and Quark Express while not actually offering anything decent in terms of real functionality.
It has always just been an alternate interface to the Word "engine" and functions that Word already had, with a few very basic templates thrown in that could have easily been included in Word. Every single thing that Publisher does can be done in Word, in fact I would say much more can be done in Word.
Don't believe me? Look at Microsoft's own brochure design templates online. Notice much love for Publisher? Not really...
https://create.microsoft.com/en-us/templates/brochures
Alternates?
Word can do a lot more than you might think and its files can be opened by people without Publisher. It is commercial but cross platform.
You can do a surprising amount in something like Libre Office, which is free and cross platform.
Scribus is cross platform and free. It is an excellent and very capable piece of software that can go far and above Publisher, doing things such as full magazines, but is sadly just a bit too technical for the average person and with only a handful of developers (who are mainly interested in that technical functionality rather than simplicity or accessibility) it is unlikely that it will improve much in that regard in the near future.
Affinity Publisher is commercial but affordable and not subscription based and on Mac and Windows and iPad. Affinity Publisher is a terrific piece of software, along with its sister apps Affinity Designer and Affinity Photo and they have rightly won awards. The Affinity apps have an active community and are recieving lots of developer love too. Affinity apps are quite accessible and there are videos and resources for the Affinity apps both from the developers and the community.
If you want something simple that does a much better job than publisher in almost every area, then look at Canva. It is web based.