ROM cartridges are used for games and media in general.
NES uses Ricoh 2A03 CPU of 8-bit also referred to as MOS Technology 6502 core. One of many reasons was the presence of third-party developers and a new business plan Nintendo developed from scratch, specifically for this console. Across the planet, it was sold in over 61 million copies. Luckily, it exceeds all expectations and soon became the best-selling console of all times. NES was launched a few years after the gaming console crash so it has a difficult mission to complete. The following year, Australia and Europe got the ability to purchase Nintendo Entertainment System as well.
A few months after the test sales, Nintendo launched a full console with all the accessories across the United States. Nintendo wanted to test the market in the United States before official release, therefore, they conducted a test sale in New York City, Los Angeles and several other cities across the country. Nintendo Entertainment System was released officially in Japan in 1983 and became one of the most popular gaming consoles of the time. The console was also known as Famicom and was used in Japan mostly. It is 8-bit console and it is actually an improvement of the previous console known as Family Computer or FC. Nintendo Entertainment System or NES is a known console developed completely by Nintendo in the 80s. Nintendo Entertainment System Information