As the Cacti community has been so extremely helpful to me, I really need to give back to it and contribute more than I currently do, however, due to being overworked, I'm finding it very hard

I should add this information to the wiki, but for now I'll quickly post it here. I have gathered it from various sources (websites, wikipedia, Cacti documentation (HTML), Cacti Wiki, and a bit of my own input).
* step - A time-variable data in intervals of a certain length.
* primary data point (PDP) - The value for a specific step, that has been interpolated
* consolidation function (CF) - Used to conolidate multiple primary data points (PDPs). Typical consolidation functions are average, minimum, maximum.
* consolidated data point (CDP) - The result of multiple primary data points (PDPs) after having a consolidation function (CF) applied to them.
* round-robin archive (RRA) - Stores a fixed amount of CDPs and specifies how many PDPs should be consolidated in to one CDP and which CF to use.
* round-robin database (RRD) - A database that contains multiple RRAs.
Cacti graphs are stored in a round-robin database (RRD), also known as a circular buffer, thus the system storage footprint remains constant over time.
RRDtool assumes time-variable data in intervals of a certain length. This interval, usually named step, is specified upon creation of an RRD file and cannot be changed afterwards. Because data may not always be available at just the right time, RRDtool will automatically interpolate any submitted data to fit its internal time-steps.
The value for a specific step, that has been interpolated, is named a primary data point (PDP). Multiple primary data points may be consolidated according to a consolidation function (CF) to form a consolidated data point (CDP). Typical consolidation functions are average, minimum, maximum.
After the data has been consolidated, the resulting CDP is stored in a round-robin archive (RRA). A round-robin archive stores a fixed amount of CDPs and specifies how many PDPs should be consolidated into one CDP and which CF to use.
* In other words: Multiple primary data points (PDPs) can be consolidated using a consolidation function (CF) such as average, minimum or maximum. Once the CF has been performed, the result is known as a consolidated data point (CDP). This information is stored in an round-robin archive (RRA).
After this time the archive will “wrap around”: the next insertion will overwrite the oldest entry. This behavior is sometimes referred to as “round-robin” and is the reason for the program's name.
To cover several timespans and/or use several consolidation functions, an RRD file may contain multiple RRAs. The data retrieval function of RRDtool automatically selects the archive with the highest resolution that still covers the requested timespan. This mechanism is also used by RRDtool's graphing subsystem.