Buck Converters

Can someone explain to me what the difference is between these (if any)?

http://www.mouser.com/ProductDetail/Texas-Instruments/MC34063AP/?qs=paYhMW8qfiu1umxNjP0GEg%3D%3D&gclid=CIKJ8O20n8kCFZM2gQodfvQH7g

https://www.adafruit.com/products/1065?gclid=CIaX1LjppskCFQwjHwodIvwEpg

Thanks!

Th adafruit TSR12450 is a 3-pin complete / working device.

The TI MC34063A chip needs many external components (a schematic) to work.

Gotcha. Thanks!