What is meant by a “West Marches” game?

A lot of people talk about a “West Marches” campaign.

– finish me

Link: https://rpg.stackexchange.com/questions/120770/what-defines-a-west-marches-campaign

Links to original articles:

• https://arsludi.lamemage.com/index.php/78/grand-experiments-west-marches/
• https://arsludi.lamemage.com/index.php/79/grand-experiments-west-marches-part-2-sharing-info/
• https://arsludi.lamemage.com/index.php/80/grand-experiments-west-marches-part-3-recycling/
• https://arsludi.lamemage.com/index.php/81/grand-experiments-west-marches-part-4-death-danger/
• https://arsludi.lamemage.com/index.php/94/west-marches-running-your-own/
• https://arsludi.lamemage.com/index.php/705/west-marches-secrets-answers-part-1/
• https://arsludi.lamemage.com/index.php/949/west-marches-layers-of-history/
• https://arsludi.lamemage.com/index.php/2210/west-marches-a-survivors-story/
• https://arsludi.lamemage.com/index.php/3508/west-marches-finding-the-dungeons/