Shinken are often used for iaijutsu (combat practice) and/or tameshigiri (cutting) practice and/or iaido. Shinken opposed to an iaito or mogito (an unsharpened manufactured sword for iaido practice).
"Gendaito" are handmade shinken by one of approximately 250 swordsmiths active in Japan at the moment, members of the Japanese Swordsmith Association.
These swordsmiths are limited by Japanese law to producing no more than twenty-four swords a year each. This limit, along with highly specialized skills and the need for a great deal of manual labour, accounts for the high price that a Japanese-made shinken (Nihonto) can fetch - starting from about $6,000 (US) for the blade alone, and going many times higher for genuine antique (Mukansa or Ningen Kokuho are two famous types) blades. There is also a large worldwide market for "shinken" made outside of Japan. Many collectors consider these to be somewhat worthless as collectibles (since they are not Nihonto), but some martial artists continue to purchase and use them, because of their considerably lower price, ease of acquisition, and also to spare their valuable Nihonto from what some view as abuse.
The vast majority of these are made in China, but there are custom smiths all over the world manufacturing swords in the Japanese style.