OCPP stands for Open Charge Point Protocol. It is the language that chargers use to talk to the software that manages them.
Why it matters
Without a shared language, a charger only works with its maker’s software. If that company changes its prices, closes or stops supporting your model, you may have to replace hardware that still works.
With OCPP, you can move your chargers to another management platform without touching the hardware.
What it carries
OCPP carries the everyday messages: a driver identified, a session started, energy delivered, a fault reported, a firmware update installed. It also lets the software set power limits during a session.
Which version?
Version 1.6J is the most widely deployed. Version 2.0.1 adds better security, smart charging and support for plug-and-charge. When you buy, ask which version a charger supports today and whether it can be upgraded.