The database - persistence

Data is the name we give to raw information, which is information that we cannot easily aggregate or understand. Without a way to store and meaningfully process and retrieve this data, it will always remain data and never information, which is what we actually want.

If we just hook up a sensor and display whatever data it reads, we are missing out on a lot of additional information. Let's take the example of temperature: what if we wanted to find out how the temperature was changing over time? What if we wanted to find the maximum and minimum temperatures for a particular day, or a particular week, or even within a custom duration of time? What if we wanted to see temperature variation across locations? There is no way we could do any of this with only the sensor. We also need some sort of persistence and structure to our data, and this is exactly what the database provides for us.

If we structure our data correctly, getting the answers to these questions is just a matter of a simple database query.