First, the abbreviation CfP means Call for Paper.
When there's a conference on a topic, you want as many people as possible to submit papers and panels to this conference. The more people submit, the greater chance for a good conference, through competition and variety. So you send out a CfP - a Call for Paper. CfPs are also used by journals, when you want people to send in articles for review on particular topics, by book editors when they want to make an anthology, a collection of edited articles, or in other cases when you want to create a collection of material.
A CfP basically describes the subject area, the deadline for submission, the place where the conference will be, who are organising it, and when it will be. If you want to be updated on the research being done in a particular field, and perhaps be able to contribute, you keep an eye on the CfPs.
The CfP will then be sent to as many places as possible for distribution. The calls are distributed on email lists, on paper posters, in trade journals (really big conferences) and on the front of web pages for relevant research communities. Basically, a CfP is an advertisement, just like any ad in a newspaper, only that the agency sending out the CfP normally does not have to pay to have it posted (except in those trade journals).
This means that when a CfP appears in the stream of any random website, the owners of the CfP and the website don't necessarily have anything to do with each other, just like seeing an ad for a soft-drink on television does not mean your television station has started to produce soft-drinks. Even less so, because your television provider has been paid to display the ad. So basically a CfP is an announcement, and it's published as a service to the general public, as it is made available to a much wider audience than the members of any specific community.
The same happens with jobs, and with calls for applications for research projects. This is how for instance a large research institution can publish on the front page of an organisation, without contributing any kind of funding, not even the price of an advertisement, to that organisation. The process of evaluating the papers, panels or applications falls to the organisation that issued the call, as that is also where you send your work. This is how a CfP, a research application call and a job application call can all show up on several websites without having any connection nor contributing any funding to the website where it is publised.