This refers to the GBK character encoding standard (Guobiao Kuozhan). The GBK standard contains over 21,000 Chinese characters, covering both Simplified and Traditional Chinese, as well as additional symbols. The 1-0 represents the specific font mapping version used by the system.
There is a significant difference between "free to download" and "free to use": Fzhtk--gbk1-0 Font -FREE-