Encapsulate what varies is a programming principle that suggests that code should be organized in such a way that the parts that are likely to change in the future are isolated from the parts that are unlikely to change. This is accomplished by creating interfaces and classes that separate the varying parts of the code from the stable parts.
Encapsulating what varies allows for more flexibility in the code. When changes are needed, they can be made to the encapsulated parts without affecting the rest of the code. This makes it easier to understand, test, and maintain the code.
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