What are the main differences between AWS Lambda and EC2?
Instruction: Compare and contrast AWS Lambda with Amazon EC2.
Updated
Official answer
Lambda and EC2 both provide compute, but expose different operating models.
With Lambda's standard event-driven function model, deploy a handler and configuration; AWS manages the execution hosts and scales invocations within quotas. You control application code, libraries, identity and data handling. Execution time, packaging, runtime and resource constraints shape which workloads fit. Request and allocated-duration pricing can suit intermittent work, but is not always cheapest.
With EC2, choose an instance type and operating-system image and manage the guest OS, application processes, patching and capacity strategy. AWS still manages the underlying physical infrastructure. Auto Scaling and managed services can automate parts of operations. On-Demand, commitment and Spot options have different cost and interruption tradeoffs.
EC2 supports long-running processes and broader OS/hardware choices. Durable storage still needs deliberate design: EBS or external services differ from ephemeral instance-store storage, and an instance is not automatically a backup. Lambda applications can also use durable external databases and object storage; persistent business data is not exclusive to EC2.
For example, a sporadic upload processor may fit Lambda, while a sustained custom server or specialized long-running computation may fit EC2 or containers. Compare actual runtime constraints, latency, sustained utilization, failure recovery and total operational cost. New Lambda compute modes can change the comparison, so name the mode being evaluated.