What is the difference between Lambda and Lambda proxy?

Does AWS have reverse proxy?

I want to proxy some requests from ec2 instance to the web app server located in EC2.

But I do not want to open port 80 on aws security group. The solution could be something like reverse proxy. Please let me know if AWS does have this option? Or is there any other alternative.

Yes, Amazon Web Services has a built-in reverse-proxy service you can use to do what you want: Elastic IP's. However, there is some caveats about them: AWS reverse-proxy has limits on how many reverse-proxies you can make (1000/5) or 4% of your total instances. If one gets blocked then all of your servers that were behind it will also fail. The IP's are per account and can't be deleted or moved.

What is AWS Lambda proxy?

How does AWS Lambda proxy work?

I'm trying to understand how the Proxy Pattern works using AWS Lambda. I did some research on the Internet but have been unable to come up with a clear picture. Does anyone know where I can find out more? Here is what I've done so far:

What are the different types of functions that are supported on AWS Lambda? I found a list at but not sure if that represents the full list. How does it work? At least the parts that I understand, as a developer, is that I create a AWS account, and upload my code to S3. My Lambda function then references files in S3. When I make changes to my code, I need to re-deploy my Lambda function. What I don't understand is how my function handles and executes requests from the API Gateway, how this whole process works in general? Is the Lambda function directly invoked by API Gateway? I suspect not, but am still trying to understand it.

A very interesting article I came across recently was Building scalable API applications with AWS Lambda & API Gateway, in which it mentions that API Gateway passes in the lambda function with all the context info as HTTP headers. I am still a bit confused about how the proxy pattern fits in here, as I don't understand what API Gateway is communicating to the Lambda function to trigger it (if API Gateway is communicating with Lambda directly, what happens to Lambda when an HTTPS request is made?) I realize that the questions may be broad, and I would welcome a little help. Thank you! UPDATE: Thanks to answer provided by Michael, and the clarification from Adam K., I now understand how AWS Lambda proxy work. It's very similar to Node JS proxy. It has its own context-object in its memory space, and provides a facade on top of it.

What is the difference between Lambda and Lambda proxy?

I have read many articles and all of them were just not clear enough.

Please please make this super obvious for the newbie, like if there is difference like how much memory is allocated by proxy and lamda and if there any advantages other than performance (the example I gave in above question are there only). A lambda statement is a shorthand syntax for defining anonymous function, while a lambda proxy calls the actual lambda in order to resolve the variable names. These are very different things! With respect to scalability: they are roughly the same, when it comes to memory consumption. The difference is really that with the proxy, those names are resolved and bound directly at declaration time. A lambda has them resolved to the values at run-time.

Performance-wise, a proxy is likely to be more performant because it is able to generate bytecode directly, but there really is no objective difference between their performance. The JVM will choose one or the other for you, as best it can based on compiler analysis and available optimisations.