In general
Sildenafil, which is the main ingredient in both Viagra and sildenafil, is what makes them work. Viagra is the brand name for a drug made by Pfizer. Sildenafil, on the other hand, is a generic drug that can be made by many companies. Because they both contain the same active ingredient, they work the same way.
Cost is often the biggest difference. Most of the time, generic drugs are less expensive than brand-name drugs because they don't have to pay as much for brand creation and marketing. Both types are put through a lot of tests to make sure they are safe and effective. For those who care a lot about cost, generic sildenafil might be a good choice. However, it's very important to talk to a medical professional to find the best and safest choice for your specific health needs and concerns.