Places in a GEDCOM are just text. Every program stores whatever was typed. Over years, and across imports from other people's files and other websites, the same town gets typed every way there is:
Boston, MA
Boston, Mass.
Boston, Massachusetts
Boston, Suffolk, Massachusetts, USA
Boston, Suffolk, MATo a naive program, that is five places.
What GED-VIEW does about it
GED-VIEW's built-in geocoder knows towns and villages worldwide under the names they have had, in many languages and scripts, historical names included (Königsberg for what is now Kaliningrad, Danzig for Gdańsk, Beč or Wien for Vienna), plus former countries and provinces such as Yugoslavia or Prussia. So most of these spellings resolve to the same location and land on the same pin on the map, and the pin lists each spelling with its count. This runs entirely in the browser; nothing is sent anywhere.
The spellings themselves stay distinct. Each different string in the file is its own entry in the Places list, because each is a different piece of text in your data. GED-VIEW points the variants out instead of silently merging them: the Issues page flags place names that look like the same place spelled differently, places recorded under different parent places, and places it could not locate at all.
It is not perfect. A common village name with nothing to tell it from its namesakes, a spelling the data does not have, or a place that exists only in your file (a farm, a house) ends up unlocated or pinned to a broader area. Geocoding by the borders a place had at the date of the event is planned.
Finding what it could not resolve
The Places list shows every distinct place string with a count. Search for a town and see how many entries come back. The Issues page reports likely variants and lists places that could not be located.
Fixing them in GED-VIEW
Tools > Standardize places and dates rewrites the variants, one proposal at a time, with the site's place data doing the recognizing. It works part by part: the town is unified, while a cemetery plot in front of it and the country after it stay as they are. A part the data recognizes keeps the name you wrote: it is unified only with the same name spelled or capitalized differently (the most frequent spelling in your file wins, or the name in a language you choose, country names included), so Mačva stays Mačva even where the data calls the district something longer. Commas are put between the parts the data recognizes in a place typed without them, and coordinates are added to every place the data locates. Optionally the country is added to a place that names none. Historical names are left alone: Königsberg stays Königsberg. Two names that differ, even by one letter, are two places.
Every proposal is a row, "was → will be", with the "will be" editable, so you can type your own; nothing is accepted until you tick it. The dates in the same file can be tidied at the same time: a date typed as numbers or in a loose form becomes strict GEDCOM, and a date that reads two ways (3/4/1901) is listed separately with both readings. The date format guide covers that half. The endings are the same as every tool: Download, Open in app, or Preview on every page and Accept. The original file is never modified.
Fixing them in the desktop program
Every desktop program has a place list with a merge or rename function. RootsMagic has a Place List with a merge button. Family Tree Maker has a Places workspace where one place can be resolved to another. Gramps has a place editor with hierarchy. Legacy has a Master Place List with a Combine option. Ancestry and MyHeritage suggest a standard place when a fact is edited.
Whatever convention you use, keep it consistent within your own file. If you record historical names, or a particular structure, that is fine; the important thing is that the same place is spelled the same way each time it appears.
Then re-export and check the Places page again.
Next
Open Places, search for the town your most common surname comes from, and count the entries. Then open Standardize places and dates and see what it proposes for them.