The oil which contains cannabinoids, including CBD, is usually called Hemp Oil, CBD Oil or Hemp Extract, which are synonyms. But it is never called Hemp Seed Oil.
Hemp Seed Oil
Regular Hemp Seed Oil is used for food or for cooking and has no CBD inside.
It could be mixed with CBD oil or CBD isolate, but that would be surely stated on the label. For example, H Drop CBD oils include hemp seed oil as carrier oil to reduce CBD level of 80% Hemp Extract and achieve accurate concentration (5% or 15%).
Hemp Seed Oil is made from hemp seeds only.
Even though still beneficial because of Omega-3, Omega-6, Vitamin E elements composition, seeds themselves have virtually no cannabinoids inside.
Hemp flowers and leaves do.
Hemp Oil, Hemp Extract and CBD Oil
Hemp Oil and Hemp Extract are the same and will usually mean oil made from hemp flowers or leaves, rich with CBD.
However, be aware of concentration, stated on the bottle – it usually varies from 1% to 20% CBD. Or from 100mg to 6000mg CBD. The greater the value, the stronger and more effective is the oil.
CBD Oil is also usually a synonym of Hemp Oil and Hemp Extract. We say "usually", because it could be theoretically made from synthetic CBD or the psychoactive cannabis, instead of hemp.
So, make sure the product is made from your preferred material before purchasing.