Here is a fact that surprises people new to solar: the electricity a panel makes cannot directly power your toaster. Panels produce direct current (DC). Your home and the grid run on alternating current (AC). Bridging the two is the job of an inverter, and the design choice around that one device is the whole Enphase story. Its Form 10-K for fiscal 2020 lays it out.
The conventional approach is a 'string inverter': you wire many panels together in a series 'string' and run them all into one large inverter on the side of the house. It is cheap and simple. Its weakness is that the panels are chained together, so the string tends to perform at the level of its weakest member. A shadow from a chimney, a leaf, or one underperforming panel can pull down the output of the whole string.
Enphase's answer is to make the inverter tiny and put one on the back of every panel — a microinverter. Now each panel converts its own DC to AC right there and operates independently. Shade on one panel only costs you that panel; the rest keep producing at full tilt. The same architecture makes the system more granular to monitor, because you can see each panel's output, and easier to expand one panel at a time.
The 10-K shows the company extending that platform beyond the inverter. It describes the Encharge home storage systems — the filing names the Encharge 10 and Encharge 3, with scalable usable capacity — which pair the microinverter approach with batteries so a home can store its solar and ride through outages. The strategic thread is a single integrated home-energy system rather than a box of unrelated parts.
There are trade-offs an honest explainer should name. Putting electronics on every panel means more devices on the roof, and historically microinverters carried a cost premium over a single central inverter. The company's argument, in the filing, is that the energy gains, monitoring, safety and expandability justify it. Whether that holds for a given installation is a project-level judgment.
If you want the real description of how Enphase's products fit together, the annual report is the place — not a spec card. The filing, indexed through tools like EdgarBeast, is the document that defines the product line in the company's own words.