What are allophones?

Some articles on allophones, allophone:

Maidu Language - Phonology - Vowels
... Back High i y u Mid e o Low a These six vowels are characterized by several different allophones depending on the phonetic environments in which they occur (initial/noninitial, stressed ... The lowest and most central allophones occur in unstressed closed syllables ... According to Shipley, (a) and (y) have allophones that almost converge once they have centralized, (i) and (u) have allophones that barely centralize and drop slightly lower, approaching and ...
Standard Chinese Phonology - Consonants
... may occur as /n/'s allophone before, when speaking quickly ... commonly viewed not as independent phonemes but as either (1) consonantal allophones of "medial" high vowels (i.e ... Some linguists prefer to classify as allophones of one of the other three series ...
Cherokee Language - Phonology - Consonants
... There is some variation in how orthographies represent these allophones ... used in the table represents the aspirated allophones as th, kh, and tsh ... Another common orthography represents the unaspirated allophones as d, ɣ, and dz and the aspirated allophones as t, k, and s (Scancarelli 2005359–62) ...