Versioning and aliases
In the real world, we often have different environments to work out of, for example development, QA, staging, pre-production, production, and so on. Having to manage a single Lambda function across all these environments can be a real pain, and also tricky especially, when each of your environments provide different configuration options, such as different connection strings for databases hosted for development and production, different roles and resource settings.
Lambda thus provides few add-on services that help you better categorize, and manage functions in the form of versions and aliases.
Versioning is a simple way to create one or more versions of your working Lambda code. Each version that you create is basically a snapshot of your origin function. Versions are also immutable which means, that each version you create from the origin or [$LATEST]
branch cannot be edited or its configuration parameters change as well. Lambda assigns simple incremental version numbers...