Static builds provide one self-contained .exe file for each program (ffmpeg, ffprobe, ffplay).
Shared builds provide each library as a separate .dll file (avcodec, avdevice, avfilter, etc.), and .exe files that depend on those libraries for each program
Dev packages provide the headers and .lib/.dll.a files required to use the .dll files in other programs.
If you are confused about what build type you need just download a static build.
To extract any of the builds you will need to download and install 7-Zip.
All builds on this page are licensed as GPL 3.0, but FFmpeg can be compiled as LGPL 2.1, LGPL 3.0, and GPL 2.
Complete a quote request to receive pricing information for a custom build.