I do desire to step into robotics in the future (after completions) and had the following question in my mind:
Do robots usually have databases (similar to these of websites in quality and quantity) and if so, please give a practical example what are they using for? Maybe in the context of machine vision or machine motion.
All the answers here are good in my opinion. If I could I would accept all of them, I suggest to start by reading the answer of user16549 which makes an introduction to DBs in robots, then continue to the answer by FooTheBar, and then read other answers.