When we give names to new inventions, discoveries, places, and a host of other things, inspiration often comes from the names of the people who came up with the inventions, made the discoveries, and so on. In other cases the name can be a tribute to the person in question, even though that person had no hand in the thing’s creation.
The words for these things are called eponyms and many of them have been added to the Cambridge Dictionary.
At a simple level, the name of the person (or sometimes an anglicized or altered version of it) becomes the name of the thing. We say that the thing was named after (or in American English named for) the person. Examples are the SI units: volt, hertz, sievert, watt, and joule, named after the scientists who had a hand in their development; and inventions the Biro, the Jacuzzi, and the diesel engine, invented (or co-invented!) by László Bíró, Candido Jacuzzi, and Rudolf Diesel. The sandwich was popularized by a Lord Sandwich; and the peach Melba was dedicated to an Australia opera singer, Nellie Melba.
Names of places are frequently eponyms; suffixes like –land, –town, etc. can be added. Maryland was named after the wife of King Charles I of England (she never went there). America comes from the name of one the first European explorers, Amerigo Vespucci. Queen Victoria gives her name to numerous places, from a state in Australia to a city in Canada to a train station in London.
The suffix -ism can be added to indicate a philosophy, religion, political movement, etc. that is associated with a particular person. Examples include Buddhism and Marxism. In some cases the –ism has a negative connotation, as in McCarthyism. The suffix -ism changes to -ist when you are talking about someone who follows a particular philosophy, religion, etc: Buddhist, Marxist.
Adjectives can be formed from eponyms, too, usually by adding suffixes like –an, –ian, –ean, and –esque. Examples are common in the arts: the Dickensian novel (from the writer Charles Dickens), a Wagnerian opera (from the composer Richard Wagner), or Cartesian logic (from the philosopher René Descartes).