Breath support is the basis for everything in singing. If you do it properly you should have zero tension in your throat. It’s also the reason you can make a sound in the first place because without moving air, there’s nothing to vibrate the vocal cords.
The chart illustrates the working ranges of three groups of instruments and the human voice. To help find the range of instruments and human voices on the piano and musical staff, vertical lines mark the location of C at intervals of an octave. Instruments and voices can exceed these ranges.