AWS Lambda Function Versioning and Aliases - AWS Lambda
docs.aws.amazon.com/lambda/latest/dg/versioning-aliases.html?adbsc=social_20151030_54349696
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Versioning allows you to better manage your in-production Lambda function code allowing you to publish one or more versions of your Lambda function. This enables you to work with different variations