A lambda function is a like a little island, surrounded by network. Unlike Fargate containers, of EC2 instances, they do not have EFS, EBS or some other fast storage support. Everything that goes into a lambda, goes in via the network interface (and network only). And hence, since Lambda’s are ephemeral, everything going in and out of the lambda has to transverse that network...
Just a collection of stuff (mostly from my old blog)