What is Classical Guitar?
You can generally tell a classical guitar by its strings, primarily nylon. It has six strings and the base is acoustic. Tones resonate from a soundboard. Typically the modern classical guitar is larger than an electric guitar design.

How to Play a Classical Guitar
Strings are plucked by the fingernails or the fingertips. The thumb traditionally plucks the base or root notes where as the fingers ring the melody and its accompanying parts. Classical guitar performers do not usually use their pinkies because of it being too small and a pick is never used. Performing a classical guitar composition requires knowledge of the historical and social influences of the time period it was written in to give it the correct interpretation.

Time Periods
• Baroque guitar – 17th to mid 18th Century. Derived from the 15th Century 4-double-string guitar called the vihuela de mano and the Renaissance 5-string.
• Early Romantic guitar – 19th Century music from the Classical and Romantic periods. One of the first 5-string guitars was built in 1779 by Gaetano Cinaccia in Naples, Italy. Some of the most famous classical guitarists, like Fernando Sor (1778-1847) lived in 19th Century, considered the golden age of the guitar.
• Modern Classical guitar – 20th Century through present day. Also known as the Spanish Guitar, these guitars have a thinner sound board giving it more amplification and tone. During this time, composers who did not play guitar began to write music for classical guitar.

See - Types of Guitar