Quick Bytes: Explain database to a 5 year old

Explain databases to a 5 year old

Explain databases to a 5 year oldQuick Bytes is a series of quick interview questions and answers. Got a question you want covering? Email us!

How would you explain what a database is to a 5 year old?

I absolutely love this question. I was given it in an interview some moons ago and thought it was brilliant.  It’s a really good question to throw a candidate off; everyone’s always prepared for technical learn-by-rote questions, and they (should be) prepared for the “how many grains of sand in the world” type questions, but this treads a line straight down the middle.  Even better, it’s a really valuable question to ask as it has direct relevance to a candidates ability to do their job.

Although there aren’t many 5 years olds in the average dev shop, the whole point of this question is that it is testing your ability to talk to non technologists.  In almost all roles you’re going to be interacting with business, marketing, HR, or some other department full of people that will have never seen Firefly and won’t have a clue what Linux is.  Interacting with these people is immensely important; if you’re building in house software it may be the most important part of your job. If you can’t communicate properly with your stakeholder then it’s going to limit your ability to do your role.

I am not at this point comparing your business stakeholders to 5 year olds.  However if the question was “how would you explain what a database is to your business” people will always make assumptions based on their experiences and start talking about tables and query languages.  Explaining it to a 5 year old makes the question much easier to answer. You can’t use anything complicated, you can’t assume any prior knowledge.  How do you answer it?

My Model Answer: The Toy Box

A database is like a very special toy box.  You put all of your toys into the box and it shuffles everything around and puts them in order.  You can then ask the toy box for any toys you want and it will find them for you really quickly.  You could ask for all of the red toys and it will find them for you. Or all of the toys that make loud noises. Or all of the red toys that make loud noises that you’ve not played with for a year.

Not Model Answers and things to avoid

I’ve heard some pretty poor answers in my time.  The moment you mention any of the following keywords you’ve lost this question

  • Query Language/SQL
  • Data
  • Storage
  • Query
  • Index
  • Sharding

People really do say these things. They panic. You have to be able to succinctly describe databases then decompose that to a toddler level.  I think sometimes people get stuck at the translation.  Take hope that it genuinely isn’t an easy question if you’re not prepared for it, but if you do crush it then you’ll score serious brownie points.  Take your time answering this one. There’s no rush. Imagine a small child actually standing in front of you. What would you say?


Take a look at some other things and come up with Explain-like-I’m-5 descriptions: start with Message Bus and Object Oriented Programming.


Image from Ryan McGuire

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