MATLAB Compiler enables you to share your MATLAB programs as standalone executables (.exe) that run against a MATLAB Runtime. It supports most of the features in MATLAB, including graphics, and protects your intellectual property by encrypting your MATLAB code.
MATLAB Compiler SDK extends MATLAB Compiler by the ability to provide shared libraries (.dll, .so), so that your MATLAB programs can be packaged into software components for integration with other programming languages.
MATLAB Coder on the other hand, provides readable and portable C source code. It supports a subset of the MATLAB Language focused on algorithms performing numerical computations.
The high-level differences between the two approaches are summarized below: