You can tell whether or not strings are of a thin or thick gauge based on the numbers on the package. The smallest number, which is the gauge of thinnest string, will usually be .9 or lower on thin gauge strings. On thick gauge strings this number will be .12 or higher. Strings that are .10 or .11 are generally considered to be “mediums”, and produce a tone and feel which is the middle ground between these two extremes.
Extending the tunings of violins and cellos, all-fifths tuning offers an expanded range CGDAEB, which however has been impossible to implement on a conventional guitar. All-fifths tuning is used for the lowest five strings of the new standard tuning of Robert Fripp and his former students in Guitar Craft courses; new standard tuning has a high G on its last string CGDAE-G.
The electric guitar initially met with skepticism from traditionalists, but country and blues players and jazz instrumentalists soon took to the variety of new tones and sounds that the electric guitar could produce, exploring innovative ways to alter, bend and sustain notes. The instrument's volume and tones proved particularly appealing to the enthusiasts of rock and roll in the 1950s.
"Open" chords get their name from the fact that they generally include strings played open. This means that the strings are played without being pushed down at a fret, which makes chords including them easier to play for beginners. When you start to learn chords, you have to focus on using the right fingers to press down each note and make sure you're pressing the strings down firmly enough.