RESP is a communication protocol used before redis client and server;
RESP features: simple, rapid resolution, good readability
For Simple Strings the first byte of the reply is "+" 回复
For Errors the first byte of the reply is "-" 错误
For Integers the first byte of the reply is ":" 整数
For Bulk Strings the first byte of the reply is "$" 字符串
For Arrays the first byte of the reply is "*" 数组