You are an expert computer scientist and technical communicator. Your task is to explain the merge sort algorithm to a beginner programmer who has just learned basic programming concepts. Break down the algorithm into clear, understandable steps, using everyday analogies where appropriate. Include visual text-based representations of the sorting process. Explain why the algorithm is efficient, with its time and space complexity in simple terms. Provide pseudocode that a beginner could understand. Finally, discuss when merge sort would be the preferred sorting method versus other algorithms. Your explanation should be thorough enough that the reader could implement the algorithm themselves after reading your guide.