What is the essence of the DRY principle and how does it contribute to improving the software development process?

The DRY principle (Don't Repeat Yourself) means "do not repeat yourself." Its essence is to avoid duplication of code and logic in a program. Instead of copying and pasting identical code fragments, repetitive functionality should be extracted into separate functions, classes, or modules.

This improves the development process by:

• Reducing the number of errors, as changes need to be made in one place.
• Increasing code readability and maintainability.
• Facilitating testing and expanding functionality.

For example, if you need to calculate the sum of array elements in multiple places, it's better to create a sumArray function than to copy the addition code everywhere.