AWS cheat sheet – Important AWS concepts explained in short

Hello cloud devs! In this blog we have come up with a cheat sheet for you to quickly revise important AWS concepts whether you have your cloud practitioner certificate exam tomorrow or an interview for a cloud developer role. This cheat sheet can be really helpful.

1. Types of cloud computing services

1. Infrastructure as a service (IAAS) – These are the services related network, storage and servers. Examples – EC2, EBS, S3, VPC etc.
2. Platform as a service (PAAS) – These services are basically tools provided by cloud providers to help the developers in building and hosting web applications. Examples – AWS lambda, Elastic beanstalk, lightsail, dynamoDB etc.
3. Software as service (SAAS) – It is a cloud based model that allows users to access and use software applications over the internet. for example – Gitlab, Microsoft teams, netflix etc.
   Note:- AWS does not provide any SaaS service.

2. Types of cloud deployment Models:

1. Public cloud: A cloud service provider provides resources over the internet on pay as you go basis. Examples of public cloud – AWS , Azure , GCP etc.
2. Private cloud: A single organization owns and uses a data center for its needs over a private network. Examples – AWS VPC, VMware , IBM cloud private etc.
3. Hybrid cloud: When an organization uses a combination of private and public cloud for its applications and data then its called hybrid cloud model.
4. Multi Cloud: When an organization uses services of multiple vendors for its cloud infrastructure needs then it’s called a multi cloud model. For example – A combination AWS and Azure.

3. 6 Pillars of AWS well architected framework

• Operational excellence
• Security
• Reliability
• Performance efficiency
• Cost optimization
• Sustainability

4. Important Database services of AWS:

• Amazon DynamoDB: It is a NoSQL and serverless database service.
• Amazon DocumentDB: It is a NoSQL database service based on MongoDB. It is not serverless
• Amazon RDS and Amazon Aurora: Both of these are relational database services provided by AWS, but they differ in performance, pricing architecture etc.
• Amazon Redshift: It’s a petabyte scale data warehouse service.
• Amazon Athena: It is a serverless query service that allows you to analyze data directly in S3 using standard SQL queries.
• AWS glue: This service is used to extract transform and load data.

5. Difference between DynamoDB and DocumentDB

6. Difference between Amazon Elastic Container Service (ECS) and Amazon Elastic container registry (ECR)

Both are used to manage docker containers , difference is that ECS mainly used to run/launch and stop the docker containers whereas ECR is used to store docker images

7. AWS storage Gateway

AWS storage gateway is a hybrid cloud storage service that connects your existing on-promises storage with AWS cloud. Types AWS storage gateway :

1. Tape Gateway
2. File Gateway
   • Amazon S3 file gateway
   • Amazon FSx file gateway
3. Volume Gateway

8. Amazon VPN and Amazon VPC

Amazon VPC (Virtual Private Cloud) – Amazon VPC lets you provision a virtually isolated section within AWS cloud where you can launch AWS resources in a virtual network that you define. You can not use Amazon VPC to connect your on-premises network with AWS cloud

Amazon VPN (Virtual Private Network) – Amazon VPN solutions establish secure connections between on-premises networks, remote offices, client devices and the AWS global network

9. AWS regions and Availability zones

AWS has its data centers spread across different regions in the world. A region is a geographical group of several availability zones (AZ), each region consists of minimum 3 AZ and each AZ can consist of 1 or more individual data centers.

10. AWS Edge locations

Amazon Edge location is a site that Amazon Cloudfront uses to cache copies of your web or app’s content for faster delivery to users at any location. Edge locations are smaller data centers as compared to data centers present in Availability zones and are strategically located in different cities around the world. When end user needs some data that is already cached by Cloudfront in edge locations, it is served to user through the nearest edge location instead of going all the way to the Availability zone, thus saving time.

11. Amazon EC2 billing and purchasing options

You can use the following options to optimize your EC2 costs on the basis your usage pattern:

On-Demand instances – In on-demand instances you have to pay only for the number of seconds that your instance is running. So you have full control over the instance lifecycle – you can decide when to launch, stop and terminate it.

Savings Plans – This plan provides upto 72% discount in cost in exchange of a commitment to use a specific amount of compute power (measured in dollars per hour) for a 1 or 3 years period.

Spot Instance – Allows you to bid on unused EC2 capacity at a discounted spot price (potentially up to 90% off as compared to On-Demand price). It’s limitation is that it can be terminated automatically anytime with a two-minute warning if the spot price exceeds your bid. 

Reserved Instance – This plan provides upto 72% discount in cost in by making commitment to a consistent instance configuration, including instance type and region for a 1 or 3 years period.

Dedicated host – It is a physical server full dedicated for your use, so it can help address corporate compliance requirements. It is not cost efficient as compared to other options.

Dedicated Instances – By default, EC2 instances run on shared tenancy hardware. This means that multiple AWS accounts might share the same physical hardware. Dedicated Instances are EC2 instances that run on hardware that’s dedicated to a single AWS account. 

Difference between Dedicated host and dedicated Instance is that , in dedicated host if user has multiple AWS accounts he can host instances related to those multiple accounts on the same dedicated host. But in case of Dedicated instances user can host instances related to only a single AWS account.