XMR/BTC is a symbol showing the price of Monero (XMR) against Bitcoin (BTC), the most popular cryptocurrency out there, i.e. how much Bitcoin you need to buy one Monero.
Monero is a cryptocurrency based on the Crypto Note algorithm. It is an independent digital coin, not a Bitcoin fork. Founded in 2014, Monero is among the top 10 cryptocurrencies in terms of market cap.
Bitcoin is the most popular cryptocurrency known to date. It was first issued in 2009. Its overall capitalisation has recently reached $150B, which makes this digital currency an attractive investment vehicle.
Bitcoin and Monero prices are determined by exchanges and depend on the popularity of these digital coins as a payment and investment method. With Monero growing faster than BTC, XMR/BTC will rise. Conversely, if Bitcoin grows faster, the XMR/BTC price will fall.