Connected TV refers to a device that allows its users to stream video content through the internet to their television as opposed to traditional cable connection. Apple TV and Roku are likely the two most famous examples of this type of device.
OTT is short for “over the top,” on the other hand refers to any video content that is streamed by a user directly from the Internet. This can happen on a desktop or laptop computer, or on a smartphone, tablet, or other types of mobile devices.