Commonwealth War Graves Commission (CWGC) website https://www.cwgc.org. Some additional information from Wikipedia: https://en.wikipedia.org/wiki/Commonwealth_War_Graves_Commission. Some of the names include non-Commonwealth individuals. In my Smith example below, 6 Smiths were listed Serving under: Dutch (i.e., the Netherlands). These would be individuals who made it to the United Kingdom (U. K.) from the Netherlands, but were still considered part of the Dutch Military.
From their About Us page: https://www.cwgc.org/about-us.
The Commonwealth War Graves Commission (CWGC) honours the 1.7 million men and women of the Commonwealth forces who died in the First and Second World Wars, and ensures they will never be forgotten.
Our work commemorates the war dead, from building and maintaining our cemeteries and memorials at 23,000 locations in more than 150 countries and territories to preservation of our extensive records and archives. Our values and aims, laid out in 1917, are as relevant now as they were 100 years ago.
Here’s a map that shows the scope of their work: https://www.cwgc.org/-/media/files/cwgc/misc/misc-reports/war_graves_map_v_large.ashx?la=en&hash=2FB469D44F803EB7A9CB535B712A614B7E9C2F6E.
CWGC FAQs: https://www.cwgc.org/about-us/faqs.
Most, possibly all, of the names in their database are on Find-A-Grave. You may find more or less information on either site.
When searching for names, you may need to use initials for the first and middle names as many are only listed by initials and surname. As an example, Smith: https://www.cwgc.org/find/find-war-dead/results?lastName=Smith. You can narrow it down more as I didn’t include first name or initials.
There are numerous other filters:
First World War
Second World War
Served with (country/nationality)
Served in (military branch, including Civilian War Dead in some instances)
Country (where buried or memorialized)
Cemetery or memorial
It’s a great resource if you have family or ancestors who served in World War I or World War II, including those civilians who are buried or memorialized by CWGC.