Safety glass in a windshield is regular glass that has a clear plastic layer laminated between two pieces of standard glass, which is why it will crack. It is designed to stay together after it has broken.
Tempered glass is solid, one piece, and will break in to a gazillion very small pieces. It cannot be cut or drilled once it is tempered. The detail that you showed means your piece is solid tempered glass, 1/8" thick.
Plexiglass/acrylic is a clear, or colored, plastic product that can be cut and drilled if both are done very carefully. Usually a very dull drill works best. It is used in aircraft windshields and in many other places. It will crack and break if not drilled properly.
Lexan/polycarbonate is a clear or colored unbreakable plastic that can be bent in a metal brake, cut or drilled very easily. It makes a good window in an area where breakage is a problem but it will start to turn yellow after a period of time in the sun. It is usually a soft plastic that will scratch easily. Commonly used in safety glasses.
