A "data structure" is a way of organizing information (i.e.: collections of data) Real/Physical world examples: * A list where you add your friend's name and phone number and any other notes one by one as you get them. * A "Contacts" book where you add your friend's names but put them in the appropriate alphabetical section. * A "Rolodex" (or box of index cards) where each person get's their own card. * A grid of columns and rows you draw on graph paper where all names are in the same column, etc. Each of these is a different way to organize or structure the data. AKA: A different data structure. Each has advantages and disadvantages. * Some are easier to get started with (implement). Like the list. * Some are easier to find a name quickly (like the contact book) * Some are easier to add a new person in the middle (like the Rolodex/Index Cards) * Some take up more physical space and are harder to carry around (Like the Rolodex) You choose which to use based on your own criteria. Do you have a small number of people so a little list of 10 is fine? Do you have a large list of people (like 100) where a list would be unwieldly so you buy a little contacts book with alphabetic tabs on the side? Do you add and remove people frequently (like in a business) where a Rolodex is better? Do you need to take the numbers with you (like when you go on vacation) so a little book is better? Or do you only need the numbers when at your desk at work, where a big fat Rolodex is fine?? As far as the built in strings, integers, Booleans, etc.: Programmers generally call those data types, not data structures. Are they technically little data structures? Yeah, maybe. But it's not worth worrying about. Just call those data types and the bigger things data structures. Answer from DominicPalladino on reddit.com