What is .net deobfuscate?
.net deobfuscate means the deobfuscate of .net exe files. which was developed by .net visual studio.
In time .net files are protected by .net reflector security or smart assembly. these tools are useful for protect .net files with obfuscate.

After obfuscate any .net file it make difficult to get the source code or .net exe files.
obcuscator change many string name and value.
So that decompiler such as .net reflector unable to get the source code.

de4dot and desmart are tools for deobfuscate .net files.
de4dot is best for deobfuscate.
watch this video to how to deobfuscate with de4dot obfuscator.

https://www.youtube.com/watch?v=ncEwvQgzuQE