Programmers are responsible for solving logical problems through critical thinking. They are not required to know any programming language or syntax. Their responsibility is to prepare the algorithm or even the pseudo-code. On the other hand, coders are responsible to write the logic or algorithm in a specific programming language. They can understand the syntaxes, optimize the code, debug and run test cases, and use different libraries and modules. You can consider that defining an algorithm for a data structure is the task of a programmer while implementing the data structure in a specific programming language like Java, C++, Python, etc. is the task of the coder. It is generally preferred that a coder should be a good programmer.