What is the difference between a meatpuppet and a sockpuppet?

A sockpuppet is an online identity used for purposes of deception. The term-a reference to the manipulation of a simple hand puppet made from a sock-originally referred to a false identity assumed by a member of an internet community who spoke to, or about, himself while pretending to be another person.[1] The term now includes other uses of misleading online identities, such as those created to praise, defend or support a third party or organization.[2] A significant difference between the use of a pseudonym[3] and the creation of a sockpuppet is that the sockpuppet poses as a independent third-party unaffiliated with the puppeteer.

The term "sockpuppet" was used as early as July 9, 1993[4] but did not become common in USENET groups until 1996. The first Oxford English Dictionary example of the term, defined as "a person whose actions are controlled by another; a minion," is taken from U.S. News and World Report, March 27, 2000.[5]

https://en.wikipedia.org/wiki/Meatpuppet#Meatpuppet

The term "meatpuppet" (or "meat puppet") is used as a pejorative description of various online behaviors. The term was current before the Internet, including references in Ursula Le Guin's science fiction story "The Diary of the Rose" (1976),[24] the alternative rock band Meat Puppets, and the cyberpunk novelist William Gibson's Neuromancer (1984).[25] Editors of the online encyclopedia Wikipedia use the term to deprecate contributions of new community members if suspected of having been recruited by an existing member to support his position.[26] Such a recruited member is considered analogous to a sockpuppet even though he is actually a separate individual (i.e. "meat") rather than a fictitious creation. Wired columnist Lore Sjöberg put "meat puppet" first on a satirical list of "common terms used at Wikipedia," defining the term as "a person who disagrees with you."[27]

Nevertheless, other online sources use the term "meatpuppet" to describe sockpuppet behaviors. For example, according to one online encyclopedia, a meat puppet "publishes comments on blogs, wikis and other public venues about some phenomenon or product in order to generate public interest and buzz"-that is, he is engaged in behavior more widely known as "astroturfing."[28] A 2006 article in The Chronicle of Higher Education defined a meat puppet as "a peculiar inhabitant of the digital world-a fictional character that passes for a real person online."

Same reference site as above.

In Wikipedia's usage, a sockpuppet is the creation of the sockmaster and IS the sockmaster posting. A meatpuppet is a different person, but posting under the master's control. This can be done from different cities, different countries, and even different continents. (Not different worlds - yet.) See above reference and https://en.wikipedia.org/wiki/Wikipedia:Sock_puppetry which is the actual policy. (Commonly referred to as WP:SOCK.)