The 2017 Great American Eclipse will be a total solar eclipse. Sometimes the Sun and Moon distances are such during a potential total solar eclipse that the Moon's angular size is slightly less than the Sun's. This results in a total annular eclipse when the Sun is not completely "covered" by the Moon but a ring of light is seen around the Moon. This is a total annular eclipse. Linda and I went on an annular eclipse expedition for a total annular eclipse on 20 May 2012. You need solar filters for this type of eclipse. Unlike totality during a solar eclipse the annular eclipse lets through lots of sunlight that can damage your eyes.
Here is a video of that eclipse.