A software designer works out the steps and algorithms needed to solve a specific problem. The coder takes the design and produces the specific sequence of source code instructions need to implement the design.
Before the Software Design stage there is normally an Operation Analysis stage.
Consider an automated warehouse. The operations analyst will work out the major steps in transferring orders to the warehouse, moving the packages around the warehouse as the goods are packed, validating that everything has been packed, the packages are addressed and passed to shipping and the goods are invoiced. The software designer will work out the algorithms involved in working out what can go in each box and the rules for moving the boxes around the warehouse. The coder creates the actual code that is going to carry out the warehouse processes.
I hope this helps.
Software design is when you plan out how the software going to look like. But coding is actual making it based upon the software design.
One creates the design for the program, the other creates the program from the design.
The difference between an architect and a construction worker.
At McDonald's or Burger King, what is the difference between order taking and cash registering?
In other words, they're not separate jobs.
Coding is encryption