Bicep is a Domain Specific Language (DSL) for deploying Azure resources declaratively. It aims to drastically simplify the authoring experience with a cleaner syntax and better support for modularity and code re-use. Bicep compiles down to standard ARM Template JSON files, which means the ARM JSON is effectively being treated as an Intermediate Language (IL).
Bicep is an alternative to using terraform as Infrastructure-as-Code to programmatically create, modify or destroy Azure resources.
A productive aspect of Bicep is the ability to take a snapshot of an existing Azure resource then compile that snapshot into the Bicep language to be used as a template from which to manage such a resource.
A common usage pattern is to execute your Bicep code in an Azure pipeline to engage its definitions to manage resources