There are 2 different types of treatments: a liquid treatment and a bait station treatment
A liquid treatment is when you take a liquid termiticide, dilute it in water, and pour it around your home, creating a moat. Depending on the product, you can expect to put out about 100-200 gallons of termiticide solution around the perimeter of your home.
The idea here is that any termite that passes through the "moat" will get into the product and die. In my experience with these products they are quite powerful and will kill the termite in a matter of minutes. Because of the quick-action effect, it will kill a lot of termites, however at a certain point, the rest of the colony will pick up on the fact that all their friends are dying in these areas. They will then look for another food source, which could be your neighbor’s house or an old tree stump.
When performing a liquid treatment you (or anyone for that matter) need to make sure the termites will go through the product that is placed. So, for example, if the termites are coming up in the middle of the house through a crack in the foundation, a perimeter liquid treatment likely won't be sufficient as the termites may never move through the product.
In cases such as that, you will need to make sure that there are spot treatments performed at those areas and it may involve drilling holes in the foundation using a hammer drill or puncturing holes in the walls to directly inject a termiticide foam in order to address the points of entry.
A bait station treatment is when you place bait stations every ~10 linear feet around the exterior of your home. You want to make sure you place them as close to the house as possible.
Bait stations work a little differently than the quick-killing liquid treatments. Baits will draw the termites in to feed on the bait. Inside the bait is a termite killer. The main difference is that the chemical in the bait is designed to kill the termite over a longer period of time: weeks or months as opposed to minutes.
The benefit of this is that throughout that weeks/months time frame, the product has time to more effectively work its way throughout the colony, leading to colony elimination, rather than just killing a bunch of termites.
The most common concern with bait stations is, if you place them 10 feet apart, there's a chance that the termites still pass through and get to the house and cause damage.
While this does happen in my experience, the effectiveness of eliminating the colony combined with the rarity of this happening combine to make this a mild concern.
These are two different approaches. In my opinion the bait station approach is the best one because of its effectiveness at eliminating the colony, rather than just killing some termites. Furthermore, the bait station system is also more affordable than the liquid treatment approach.
Liquid treatments are definitely the old school standard and if you talk to the greybeards in the industry they tend to support liquid. However, with advances in technology and scientific research, baits are showing to be much more effective over the long run.
Your situation might be different and call for a different approach:
The industry standard is a product called Termidor HE.
This product is only available to licensed pest control operators but they do make a weaker version of this product called Termidor SC which would be the next recommendation if you're brave enough to attempt to treat on your own. If you're having a professional do the treatment, make sure they are using Termidor HE.
Note: there are a LOT of products that are labeled for termite treatments and approved by the EPA. Personally, I would only stick with the best when it comes to this stuff. And the incremental cost isn't that much - maybe $50-75 - to use the top-of-the-line product.
When it comes to bait stations, there are only two products that I'd recommend: Sentricon or Trelona.
Sentricon is the industry leader and was the main pioneer of these bait stations. They have the most momentum and coverage. One thing to note for Sentricon is that they are only available to a subset of licensed pest control companies.
Typically about 2% of companies are approved to be licensed Sentricon installers.
The second option in the industry is a product called Trelona, which is available to DIYers as well as pest control professionals. It's made by the same company that makes Termidor, the primary liquid termite product.
If you want to DIY it, go with Trelona and it will set you back $300-500 depending on if you have the right equipment and how many stations you need.
If you'll go with a professional installation, the pricing should be about the same, maybe a little more but the Sentricon will typically be cheaper than someone using Trelona. This is because the cost of Sentricon to the installers is typically lower than the cost of Trelona.