Why EC2 matters for compute in AWS - Visual Breakdown

Process Flow - Why EC2 matters for compute

User needs computing power

↓

Choose EC2 service

↓

Select instance type (CPU, RAM)

↓

Launch virtual server

↓

Run applications on EC2

↓

Scale up/down as needed

↓

Pay only for used compute

This flow shows how a user picks EC2 to get computing power, launches a virtual server, runs apps, and scales while paying only for what they use.

Execution Sample

AWS

Launch EC2 instance with t3.micro
Run web server on EC2
Scale instance count
Stop instance when done

This example shows starting a small EC2 server, running a web app, adjusting capacity, and stopping to save cost.

Process Table

Step	Action	EC2 State	Compute Available	Cost Impact
1	User requests EC2 instance	No instances running	0 vCPUs, 0 RAM	$0
2	EC2 launches t3.micro instance	1 instance running	2 vCPUs, 1 GiB RAM	Small hourly cost
3	User deploys web server	Instance running	2 vCPUs, 1 GiB RAM	Cost continues
4	User scales to 3 instances	3 instances running	6 vCPUs, 3 GiB RAM	Cost triples
5	User stops all instances	No instances running	0 vCPUs, 0 RAM	Cost returns to $0

💡 User stops instances, so no compute is running and no cost is incurred.

Status Tracker

Variable	Start	After Step 2	After Step 4	After Step 5
Instances Running	0	1	3	0
Total vCPUs	0	2	6	0
Total RAM (GiB)	0	1	3	0
Hourly Cost	$0	Small	Triple Small	$0

Key Moments - 3 Insights

Why does cost increase when scaling instances?

Because each EC2 instance uses compute resources billed hourly, so more instances mean more cost as shown in execution_table step 4.

Does EC2 keep charging when instances are stopped?

No, as shown in execution_table step 5, stopping instances releases compute and stops billing.

Why choose EC2 instead of a physical server?

EC2 lets you quickly get compute power without buying hardware, and you pay only for what you use, shown by the flow from step 1 to 5.

Visual Quiz - 3 Questions

Look at the execution_table, how many vCPUs are available after step 4?

A 2 vCPUs

B 3 vCPUs

C 6 vCPUs

D 0 vCPUs

💡 Hint

Check the 'Compute Available' column at step 4 in execution_table.

At which step does the cost return to zero?

A Step 2

B Step 5

C Step 3

D Step 4

💡 Hint

Look at the 'Cost Impact' column in execution_table for when cost is $0.

If the user launches 5 instances instead of 3 at step 4, what happens to the total RAM?

A 5 GiB RAM

B 3 GiB RAM

C 1 GiB RAM

D 0 GiB RAM

💡 Hint

Each instance has 1 GiB RAM; multiply by number of instances in variable_tracker.

Concept Snapshot

EC2 provides virtual servers (instances) for compute.
Choose instance type based on CPU and RAM needs.
Launch instances to run apps and scale as needed.
Pay only for running instances by the hour.
Stop instances to save cost when not in use.

Full Transcript

EC2 matters for compute because it lets users quickly get virtual servers with chosen CPU and RAM. Users launch instances to run applications and can scale the number of instances up or down. They pay hourly only for the compute they use. When instances are stopped, billing stops. This flexibility and pay-as-you-go model make EC2 a key service for cloud computing.