Below is a collection of photos showing both open cell and closed cell spray foam insulation.
In this first photo, you can see an example of open-cell spray foam insulation. Spray foam is an ideal insulation option since it expands neatly even into the tiny crevices around the window frame.
In this second photo, you can see an example of spray foam insulation being used in an attic and roofing scenario. This is an example of closed-cell spray foam. Closed-cell spray foam serves as both an excellent air and water vapor barrier.
In this third photo, it becomes evident how spray foam expands cleanly and neatly between the studs. Open-cell insulation is pefect for interior walls because it provides very good sound reduction.
As you can see in this fourth photo, it's important to use a contractor who is properly trained in spray foam application from both a health/safety perspective as well as a structure/safety perspective.
Finally, spray foam insulation that is used in both residential and commercial structures protects against moisture. This provides the benefit of reducing the chance of harmful mold and mildew. Eliminating sources of mold growth reduces the likelihood of rotting wood in a home, and subsequent allergic reactions to those mold spores.