The TV antenna has survived the introduction of cable modems and cable TV and even the age of streaming media devices. To this day, the major broadcast stations continue to send out signals for free, giving you access to some of the most popular TV shows and programs with no subscription or extra fees.
HDTV/digital signals use the same frequencies as the old analog broadcasting system. However, digital signals are less forgiving of poor antenna placement. If you live close to transmitters in your area, an indoor TV antenna will do the trick, but in more remote areas, an outdoor TV antenna mounted on the roof is going to give you better reception. For especially weak signals, use an amplified antenna to get the most coverage.
You will also want to consider whether you'd be better served by a directional antenna — which works well in areas with hills, big trees or tall buildings because it focuses on signals coming from the direction it's facing. Or, you might want to consider a multi-directional antenna, which can pull in signals from more than one transmitter.