Both words are derived from the first two letters of the Greek alphabet, alpha and beta. The Latin form was alphabetum.
In English, the term "ABCs" can be used synonymously in some contexts. The corresponding Spanish word is abecedario, which can also refer to a spelling book or a list of words in alphabetical order. The term abecé can be used in the same way, or to refer to the basics of a subject matter.
In English, the verb "to alphabetize" means to place words in alphabetical order. The corresponding Spanish word, alfabetizar can mean the same thing, but it more often means to teach reading and writing. Thus what would be referred to as the literacy rate in English is known in Spanish as the índice de alfabetización.
The letter names alpha and beta didn't originate with the Greeks, but came to Greek by way of Phoenician, a Semitic language closely connected with various languages of the Middle East such as Hebrew. The exact origins of these two letters are lost in antiquity, but it is known that the word aleph was a word for "ox" (the words "elephant" and elefante are derived from it), and beth meant "house" (some Biblical place names such as Bethlehem are derived from it).