|Suitable for long-term, steady-state operations that require full control over the environment and custom applications.
|Ideal for short-term, event-driven tasks that can benefit from automatic scaling and reduced operational overhead.
|Requires you to launch, configure and manage your EC2 instances manually or using tools like Auto Scaling Groups or Elastic Load Balancers.
|Handles the back-end provisioning, loading, execution, scaling and unloading of your code automatically based on the triggers you define (such as uploading a file to S3, making a change in DynamoDB, receiving an HTTP request to API Gateway, etc.).
|Allows you to create snapshots of your instances or volumes to backup or restore your data. You can also create custom images (called AMIs) from your instances to launch new instances with the same configuration.
|Allows you to create versions of your functions to track changes and manage deployments. You can also create aliases to point to different versions of your functions.
|Requires you to configure security groups and network access control lists to control the inbound and outbound traffic to your instances. You also need to manage the encryption of your data at rest and in transit using tools like AWS Key Management Service or AWS Certificate Manager.
|Relies on AWS Identity and Access Management (IAM) roles and policies to control the permissions of your functions. You can also use encryption helpers or AWS Secrets Manager to encrypt your data at rest and in transit.
|Performance and Availability
|Offers different types and sizes of instances to meet different performance requirements. You can also use features like Enhanced Networking, Placement Groups or Elastic Fabric Adapter to optimize the network performance of your instances. You can also use Availability Zones or Regions to improve the availability and fault tolerance of your instances.
|Offers a fixed amount of memory (from 128 MB to 10 GB) and CPU power (proportional to the memory) for each function invocation. You can also use features like Provisioned Concurrency or Reserved Concurrency to improve the performance and scalability of your functions. You can also use Regions or Multi-AZ deployments to improve the availability and fault tolerance of your functions.
|Charges you based on the type, size and duration of your instances, as well as the data transfer and storage costs. You can also use options like Spot Instances, Reserved Instances or Savings Plans to reduce your costs.
|Charges you based on the number of requests and the execution time of your functions, as well as the data transfer and storage costs. You can also use options like Free Tier or Provisioned Concurrency Pricing to reduce your costs.
I hope this helps you understand the difference between AWS EC2 and AWS Lambda better.