What was Ada Lovelace's major contribution to computing?

Ada Lovelace's most significant contribution to computing is the creation of algorithms for Charles Babbage's Analytical Engine, which is considered one of the first concepts of a general-purpose computer. In her notes on the Analytical Engine, she described a method for calculating Bernoulli numbers, which is often referred to as the first algorithm intended to be processed by a machine. This work laid the groundwork for future programming by illustrating how machines could be instructed to perform complex calculations through sequences of operations.

Her visionary ideas about the potential for machines to go beyond mere calculation and manipulate symbols for more complex processes presaged modern computing. Lovelace's insights into the capabilities of computers were groundbreaking and established her as one of the first computer programmers, reinforcing the importance of algorithms in computer science.

The other choices reflect developments that either came much later or involve different areas of computing.