“Key” refers to the first pitch of the scale that the song is based on, determining how high or low the song is pitched.  In contrast, Tonality refers to the relationship between pitches as they relate to the Resting Tone.  Dorian tonality, for example, can be in any “key,” or “keyality.”  You could sing a Dorian song from any pitch and the relationship between pitches in the song would stay the same, even though the “Key” and the range of the song would be higher or lower.  Similarly, you could sing any song in Triple meter in any tempo and the relationship between beats would stay the same, even though the song would be faster or slower.