If you have one speaker beneath the screen of your TV, it's a "soundbar." However, if the one soundbar is the hub for 5-11 speakers, it's a "soundbar system."
If you have a soundbar system, it may have better chipsets to decode the hi-def audio signal from your HD and UHD sources (Netflix, Prime, HBO, etc).
If your TV has an eARC port, connect the TV to the soundbar via eARC. Via eARC, the TV is basically "hands off" with decoding audio. The TV will separate the raw audio data and pass it to the soundbar for decoding, processing, steering, etc.
Because TV sets only provide 2-channel stereo, its audio processing stinks. Let the component engineered to process audio process the audio...especially if it's heavier data.