Can you explain them in a more concrete, conversational way?
Does this service let me e.g. take any docker image and turn it into a SaaS, handling user accounts and billing etc?
Explainers seem to not cover _why_ you would want to separate these "planes". There are several reasons, and I'm no authority, but for starters: * control messages will have different expectations around them: their amount and frequency, delivery guarantees, urgency with which they are processed. Treating this traffic separately means you can engineer appropriately for data and control traffic. * last thing you want is the control message "stop processing traffic from IP x.x.x.x port y" to be stuck behind traffic from said IP/port...
In this context, the meaning is somewhat different. They are referring to administrative traffic vs "actual work" traffic. Auth, billing/accounting, configuration updates, that sort of thing. If you are running a SaaS, and your customer is very security conscious and wants none of their precious data to ever leave their VPC, you have 2 options: deploy your software into their VPC completely, making it hard to do a variety of things like upgrades, and increasing complexity; or you can separate control actions from your "worker nodes" and storage, and only deploy the latter into the VPC. You can then work on your control panels, monitor usage, continuously evolve various admin panels and config options, etc, using normal SaaS approaches while the security conscious customer knows that their core data is not leaving their virtual walls and only "bob ran a thing and stored results" goes to the vendor.
This post is about abstracting out common bits of how one implements that, and allowing SaaS offerings to provide that sort of separation easier.
Control plane is the central lifecycle management system that helps provide all the SaaS experience for your Infra SaaS application, manages the metadata for your application and also pushes this information to all the data planes. Example of lifecycle management operations could be creating an user, a new organization, provisioning your data plane in a specific region, deleting a cluster etc.
The data plane is your product that you want to sell to your customers and control plane is the central system that helps you to make your product work in a self serve way with your customers.
This example can also be mapped to internal use cases. Many companies manage their own infrastructure internally and end up having to build a central control plane to manage all the different infrastructure that they provide as a service to their developers. Hope this helps.
Pretend we're a SaaS company offering a database as a service. Adding and removing users, and the setting of passwords is control plane stuff. In a sufficiently web scale system, adding and removing users becomes, not just its own microservice, but a collection of microservices to authenticate and send updates to the main product database, and have its own separate database.