What is e.g. marshall?

Marshall is a brand primarily known for manufacturing guitar amplifiers. The company was founded in 1962 by Jim Marshall in London, England. Marshall amps have been used by some of the most influential musicians of all time, including Jimi Hendrix, Eric Clapton, and Angus Young of AC/DC. Marshall also produces headphones and speakers for use with portable devices and computers. The brand is synonymous with high-quality, reliable audio equipment and has a large following among musicians and audio enthusiasts.