What was the first electronic digital computer developed at the University of Pennsylvania in 1946?

The first electronic digital computer developed at the University of Pennsylvania in 1946 was the ENIAC (Electronic Numerical Integrator and Computer). It was significant because it was one of the earliest machines to utilize electronic components, specifically vacuum tubes, rather than mechanical parts for processing calculations. This allowed ENIAC to perform calculations at a much faster rate than its predecessors, which were primarily mechanical or electro-mechanical devices.

ENIAC was designed to calculate artillery firing tables for the United States Army during World War II and could be reprogrammed to solve a range of mathematical problems. It marked a pivotal moment in computing history by demonstrating the feasibility and power of digital computers, laying the groundwork for future advancements in the field.

In contrast, the other mentioned options are notable in their own right but do not fit the specific criteria of being the first electronic digital computer. Colossus was an early computing device used for code-breaking but was not digital in the same sense. The UNIVAC, completed later in 1951, was one of the first commercial computers, but it came after ENIAC. The Mark I, while a significant early computer, was primarily electro-mechanical and not a fully electronic digital computer like ENIAC.