Shorter, thinner, or tighter strings sound higher in pitch than longer, thicker, or looser strings.
First string is the thinnest, tightest string.
The Home tonality, Home Plate, Home in the Neighborhood, The place you return to. On the piano the diatonic C scale uses only the white keys. In written music the Key Signature indicates the sharps or flats that are contained in the Diatonic scale for that key.