What are algorithms and data structures? What are the differences between them? Which one is more useful and why?

 Algorithms are step-by-step procedures for solving problems, while data structures are ways of organizing and storing data.

 The choice of algorithm and data structure depends on the problem being solved and the desired efficiency. 

Both algorithms and data structures are essential for efficient computer programming. It's not possible to say which one is more useful as both are needed for effective software design.