A source release （源代码版本）will be compiled on your own machine while a binary release（二进制发布版本） must match your operating system.
source releases are more common on linux systems because linux systems can dramatically vary in cpu, installed library versions, kernelversions and nearly every linux system has a compiler installed.
binary releases are common on ms-windows systems. most windows machines do not have a compiler installed.
Other Answer:
1-Binary releases contain computer readable version of the application, meaning it is compiled. Source releases contain human readable version of the application, meaning it has to be compiled before it can be used.
2-The source release is the raw, uncompiled code. You could read it yourself. To use it, it must be compiled on your machine. Binary means the code was compiled into a machine language format that the computer can read, then execute. No human can understand the binary file unless its been dissected, or opened with some program that let's you read the executable as code.