For the most part, there are three major types: inserts, screens, and toppers. Gutter guards go by many names, including the following:
Inserts are the most cost-effective option and the easiest to install by pretty much anyone. They simply drop down into your existing gutter. No installation beyond that, and no skills or tools required. They are typically made out of a foam, wire mesh and have a porous-like quality to them. While they are the cheapest option, they are also the highest maintenance, because they have to be pulled out and cleaned or else they’ll clog with fine debris and lose efficacy.
Of the three types of gutter guards, screens are the most popular. They cover your existing gutter with a screen that allows water to pass through while blocking debris. Like all gutter guards, screens will need to be removed and cleaned routinely as well. Screens vary in cost and installation expenses.
Gutter toppers are the most expensive option but also the most effective and lowest maintenance. They have a curved or dome shape, typically, and provide protection over the top of the gutter. They divert water over and around into a small slit between the gutter and the topper. Most toppers require maintenance like all gutter guards.