Kaltura OVP and OTT

We are using the Kaltura Community Edition for an internal project.
As per my understanding this is the Kaltura OVP.
We would want to know the difference between Kaltura OVP and Kaltura OTT.
Are the APIs different for both? We have got the APIs for Kaltura OVP, but could not find any for OTT.
Also are the HTML players different for Kalrura OVP and Katura OTT ?

Hello,

The OTT is another product and is not FOSS. Its APIs are entirely different.
If you are interested in purchasing it, please contact our sales department via www.kaltura.com.

Thank you for the response.
We will get in touch with the Katura Sales team.
As the APIs are entirely different there would be considerable amount of effort involved if we have to move from OVP to OTT.
Are the HTML players also different for Kalrura OVP and Katura OTT ?

What is FOSS ? Also, you mention that the APIs are entirely different. Can you please provide resources that document the both APIs? I am for example trying to understand if OTT Player is capable of captions? I can see the OVP Player does show “CC” as soon as the asset is equipped with a VTT file, but with the OTT Player this seems to not be true.