Assuming it’s a modern TV, they are essentially computers and need to “boot up” the same way a computer does. This process involves loading things into memory and, though I’m no expert in the subject, I suspect when you turn it “off” you are in fact putting it to sleep instead. This would leave all the data loaded and ready to go should you start it back up in a couple minutes. I then suspect after a set amount of time, it actually turns off to save power, dumping the memory.
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