An early TV was deactivated by using a power switch. This functioned in the same way as unplugging the television. Remote controls were popularized in older systems that used conventional transformers. These systems often ran hot even when the system was turned off. They wasted significant power when turned off. Modern TVs are powered by switching power supplies. Most of them require little standby power, so it is probably not worth the effort to unplug between use. An Amp meter can help you determine which type of system you have.