The most accurate definition of the CD is stated by Jez Humble and reads as follows:
"Continuous Delivery is the ability to get changes of all types—including new features, configuration changes, bug fixes, and experiments—into production, or into the hands of users, safely and quickly, in a sustainable way."
This definition covers the key points.
To understand it better, let's imagine a scenario. You are responsible for a product, let's say, the email client application. Users come to you with a new requirement: they want to sort emails by size. You decide that the development will take around one week. When can the user expect to use the feature? Usually, after the development is done, you hand over the completed feature first to the QA team and then to the operations team, which takes additional time, ranging from days to months...
