In August 1993 Wizards of the Coast released the 1st wave of its initial print run, which came to be known as "Alpha". This first printing contained 295 unique cards, and was a very small order of just 2.6 million cards total.
The easiest way to distinguish these cards from the 2nd printing known as "Beta", is the extra rounded corners on Alpha cards.
However there were numerous changes made between print runs, and as a result many Beta cards were changed before they were printed.
This is a visual guide to these changes, showing the 23 cards which have noticeable template changes between Alpha and Beta.
Circle of Protection Red
Birds of Paradise
Force of Nature
Red Elemental Blast