I am struggling to find this on the web.
Baseline is a snapshot; a position or situation that is recorded. Although the position may be updated later, the baseline remains unchanged and available as a reminder of the original state and as a comparison against the current position. Products that have passed their quality checks and are approved are baselined products.Anything ‘baselined’ should be under version control in configuration management and ‘frozen’, i.e. no changes to that version are allowed.