What is Amazon S3, in plain words?

What it does

• Stores anything. Photos, videos, documents, music, backups, computer code.
• Never runs out of room. One text file or billions of videos, the locker grows with you, and nobody ever tells you the drive is full.
• Works from anywhere. Any device, anywhere in the world, with an internet connection and permission to open the files.
• Keeps copies. Amazon stores each file in several data centres at once, so a failed disk does not lose it.
• Charges as you go. There is no fixed drive to buy. You pay for the exact space your files take up, by the month, which Amazon calls storage and this course calls rent.

What the name means

S3 stands for Simple Storage Service, the three S words that describe it. Simple, because it does one thing. Storage, because that thing is keeping files. Service, because Amazon runs it and you rent it.

The words you will hear

• A bucket is one locker. You can have one or thousands, each with its own name.
• A key is the name of a file inside a bucket, folder path included.
• The console is the website where the people who run the Amazon account set things up.

What it costs, in three lines

$2.30a month

keeping 100 GB, about 25,000 phone photos or 100,000 Word documents

$0.005per 1,000 fetches

each time a file is read or listed; most teams never notice this line

$0.09per GB out

files leaving Amazon for the internet, after the first 100 GB a month

Keeping files is the cheap part. Most surprises on an S3 bill come from files leaving.

The locker was designed for programmers, so the console assumes you are one. Lessons 4 and 5 are about the other doors in.