Here's everything we covered in our Second session together. Part 1 What is Data? We covered what data is, how it gets generated, and why it lives in memory before it ever reaches a database — and what happens when it doesn't make it. Part 2 Operational Databases & ACID We explored why operational databases exist and unpacked ACID — the four rules that stop two people withdrawing £1,000 each from an account with only £1,000 in it, at the same time, from different locations.