AWS in Plain English!

Run an App Services No matter what you do with AWS you'll probably end up using these services as everything else interacts with them.
EC2
Should have been called Amazon Virtual Servers	Use this to Host the bits of things you think of as a computer.	It's like http://www.linode.com","It's handwavy, but EC2 instances are similar to the virtual private servers you'd get at Linode, DigitalOcean or Rackspace.
IAM
Should have been called Users, Keys and Certs	Use this to Set up additional users, set up new AWS Keys and policies.
S3
Should have been called Amazon Unlimited FTP Server	Use this to Store images and other assets for websites. Keep backups and share files between services. Host static websites. Also, many of the other AWS services write and read from S3. S3 in Plain English  S3 Buckets of Objects
VPC
Should have been called Amazon Virtual Colocated Rack	Use this to Overcome objections that "all our stuff is on the internet!" by adding an additional layer of security. Makes it appear as if all of your AWS services are on the same little network instead of being small pieces in a much bigger network.	It's like If you're familar with networking: VLANs
Lambda
Should have been called AWS App Scripts	Use this to Run little self contained snippets of JS, Java or Python to do discrete tasks. Sort of a combination of a queue and execution in one. Used for storing and then executing changes to your AWS setup or responding to events in S3 or DynamoDB. Lambda in Plain English
Web Developer Services If you're setting up a web app, these are mostly what you'd end up using. These are similar to what you'd find in Heroku's Addon Marketplace.
API Gateway
Should have been called API Proxy	Use this to Proxy your apps API through this so you can throttle bad client traffic, test new versions, and present methods more cleanly.	It's like 3Scale
RDS
Should have been called Amazon SQL	Use this to Be your app's Mysql, Postgres, and Oracle database.	It's like Heroku Postgres
Route53
Should have been called Amazon DNS + Domains	Use this to Buy a new domain and set up the DNS records for that domain.	It's like DNSimple, GoDaddy, Gandi
SES
Should have been called Amazon Transactional Email	Use this to Send one-off emails like password resets, notifications, etc. You could use it to send a newsletter if you wrote all the code, but that's not a great idea.	It's like SendGrid, Mandrill, Postmark
Cloudfront
Should have been called Amazon CDN	Use this to Make your websites load faster by spreading out static file delivery to be closer to where your users are.	It's like MaxCDN, Akamai
CloudSearch
Should have been called Amazon Fulltext Search	Use this to Pull in data on S3 or in RDS and then search it for every instance of 'Jimmy.'	It's like Sphinx, Solr, ElasticSearch
DynamoDB
Should have been called Amazon NoSQL	Use this to Be your app's massively scalable key valueish store.	It's like MongoLab
Elasticache
Should have been called Amazon Memcached	Use this to Be your app's Memcached or Redis.	It's like Redis to Go, Memcachier
Elastic Transcoder
Should have been called Amazon Beginning Cut Pro	Use this to Deal with video weirdness (change formats, compress, etc.).
SQS
Should have been called Amazon Queue	Use this to Store data for future processing in a queue. The lingo for this is storing "messages" but it doesn't have anything to do with email or SMS. SQS doesn't have any logic, it's just a place to put things and take things out.	It's like RabbitMQ, Sidekiq
WAF
Should have been called AWS Firewall	Use this to Block bad requests to Cloudfront protected sites (aka stop people trying 10,000 passwords against /wp-admin)	It's like Sophos, Kapersky
Mobile App Developer Services These are the services that only work for mobile developers.
Cognito
Should have been called Amazon OAuth as a Service	Use this to Give end users - (non AWS) - the ability to log in with Google, Facebook, etc.	It's like OAuth.io
Device Farm
Should have been called Amazon Drawer of Old Android Devices	Use this to Test your app on a bunch of different IOS and Android devices simultaneously.	It's like MobileTest, iOS emulator
Mobile Analytics
Should have been called Spot on Name, Amazon Product Managers take note	Use this to Track what people are doing inside of your app.	It's like Flurry
SNS
Should have been called Amazon Messenger	Use this to Send mobile notifications, emails and/or SMS messages	It's like UrbanAirship, Twilio
Ops and Code Deployment Services These are for automating how you manage and deploy your code onto other services.
CodeCommit
Should have been called Amazon GitHub	Use this to Version control your code - hosted Git.	It's like Github, BitBucket
Code Deploy
Should have been called Not bad	Use this to Get your code from your CodeCommit repo (or Github) onto a bunch of EC2 instances in a sane way.	It's like Heroku, Capistrano
CodePipeline
Should have been called Amazon Continuous Integration	Use this to Run automated tests on your code and then do stuff with it depending on if it passes those tests.	It's like CircleCI, Travis
EC2 Container Service
Should have been called Amazon Docker as a Service	Use this to Put a Dockerfile into an EC2 instance so you can run a website.
Elastic Beanstalk
Should have been called Amazon Platform as a Service	Use this to Move your app hosted on Heroku to AWS when it gets too expensive.	It's like Heroku, BlueMix, Modulus
Enterprise / Corporate Services Services for business and networks.
AppStream
Should have been called Amazon Citrix	Use this to Put a copy of a Windows application on a Windows machine that people get remote access to.	It's like Citrix, RDP
Direct Connect
Should have been called Pretty spot on actually	Use this to Pay your Telco + AWS to get a dedicated leased line from your data center or network to AWS. Cheaper than Internet out for Data.	It's like A toll road turnpike bypassing the crowded side streets.
Directory Service
Should have been called Pretty spot on actually	Use this to Tie together other apps that need a Microsoft Active Directory to control them.
WorkDocs
Should have been called Amazon Unstructured Files	Use this to Share Word Docs with your colleagues.	It's like Dropbox, DataAnywhere
WorkMail
Should have been called Amazon Company Email	Use this to Give everyone in your company the same email system and calendar.	It's like Google Apps for Domains
Workspaces
Should have been called Amazon Remote Computer	Use this to Gives you a standard windows desktop that you're remotely controlling.
Service Catalog
Should have been called Amazon Setup Already	Use this to Give other AWS users in your group access to preset apps you've built so they don't have to read guides like this.
Storage Gateway
Should have been called S3 pretending it's part of your corporate network	Use this to Stop buying more storage to keep Word Docs on. Make automating getting files into S3 from your corporate network easier.
Big Data Services Services to ingest, manipulate and massage data to do your will.
Data Pipeline
Should have been called Amazon ETL	Use this to Extract, Transform and Load data from elsewhere in AWS. Schedule when it happens and get alerts when they fail.
Elastic Map Reduce
Should have been called Amazon Hadooper	Use this to Iterate over massive text files of raw data that you're keeping in S3.	It's like Treasure Data
Glacier
Should have been called Really slow Amazon S3	Use this to Make backups of your backups that you keep on S3. Also, beware the cost of getting data back out in a hurry. For long term archiving.
Kinesis
Should have been called Amazon High Throughput	Use this to Ingest lots of data very quickly (for things like analytics or people retweeting Kanye) that you then later use other AWS services to analyze.	It's like Kafka
RedShift
Should have been called Amazon Data Warehouse	Use this to Store a whole bunch of analytics data, do some processing, and dump it out.
Machine Learning
Should have been called Skynet	Use this to Predict future behavior from existing data for problems like fraud detection or "people that bought x also bought y."
SWF
Should have been called Amazon EC2 Queue	Use this to Build a service of "deciders" and "workers" on top of EC2 to accomplish a set task. Unlike SQS - logic is set up inside the service to determine how and what should happen.	It's like IronWorker
Snowball
Should have been called AWS Big Old Portable Storage	Use this to Get a bunch of hard drives you can attach to your network to make getting large amounts (Terabytes of Data) into and out of AWS	It's like Shipping a Network Attached Storage device to AWS
AWS Management Services AWS can get so difficult to manage that they invented a bunch of services to sell you to make it easier to manage.
CloudFormation
Should have been called Amazon Services Setup	Use this to Set up a bunch of connected AWS services in one go.
CloudTrail
Should have been called Amazon Logging	Use this to Log who is doing what in your AWS stack (API calls).
CloudWatch
Should have been called Amazon Status Pager	Use this to Get alerts about AWS services messing up or disconnecting.	It's like PagerDuty, Statuspage
Config
Should have been called Amazon Configuration Management	Use this to Keep from going insane if you have a large AWS setup and changes are happening that you want to track.
OpsWorks
Should have been called Amazon Chef	Use this to Handle running your application with things like auto-scaling.
Trusted Advisor
Should have been called Amazon Pennypincher	Use this to Find out where you're paying too much in your AWS setup (unused EC2 instances, etc.).
Inspector
Should have been called Amazon Auditor	Use this to Scans your AWS setup to determine if you've setup it up in an insecure way	It's like Alert Logic

AWS in Plain English

But with 50 plus opaquely named services, we decided that enough was enough and that some plain english descriptions were needed.