For CGI you have to maintain a server running Apache or some other web server software and persistent storage for a copy of your script along with a means of de

For CGI you have to maintain a server running Apache or some other web server software and persistent storage for a copy of your script along with a means of deploying them. You are limited to concurrency equal to the number of cores/threads and memory on your server or you have to manage some means of load balancing between multiple servers which you maintain along with deploying your script to each of them. Certainly you could run a cluster of servers or even an auto-scale group of servers with all of your cgi programs and handle lots of http requests. Serverless/Lambda means you don't have to do this. Also, not all lambda's are handling http requests, so you'll need to figure out the best way to deal with other events and monitor queues, etc.