This is the terminology list I wish I’d had to start with. A page with content something like this should be prominently linked in a post stickied where beginners will find it.
Input - An incoming datasource. Each input has an associated “node” identifier and a “key” sub-identifier.
You can’t really do anything with an input except hang a single chain of “feed” processes off it.
Node - a grouping identifier for your inputs or feeds.
Key - a sub-identifier for items within each Node.
Feed - A series of operations (process nodes) to execute against all new data coming to an Input. Each “process” (step) in a feed seems to get stored in a time-series database, usually either phpfina or phpfiwa.
Most of the interesting ones require php-redis, which doesn’t exist on all hosts.
Virtual Feed - A feed which hangs off any other process node.
This sounds a little more like a description for input processing than a feed.
Input process list (or input processing) A list of processes performed sequentially on each input value as it is received on that input.
Process A function that can be attached to the process list of an input to change the value or to save the value to a feed.
Feed A place where data is recorded, usually as a time series of datapoints.
I’m all for chipping in to a fuller list of terms and abbreviations used though out the project. A simple “glossary” could serve as a helpful first step into understanding OEM and emoncms, adding some links to further info and you have the beginnings of a documentation “index”, not to be confused with a “contents” list which has been discussed elsewhere