Ideas need to be translated into visuals which help turn an idea into a product. Visualising a concept means you’ll need some or all of these: sketches, illustrations, technical drawings, mood boards, line sheets …etc
Samples are prototypes made to model design ideas and made in order to finalize the pattern for production. Sampling should take place during the first phase of design (R&D) because you can’t get to selling (second phase) if you don’t have production (third phase). There are a few types of samples usually made, the main ones being prototype/toile, 1st sample, sealed/final sample, salesman sample, pre-production sample.
In sewing and fashion design, a pattern is the template from which the parts of a garment are traced onto the chosen make material before being cut out and assembled. Patterns are usually made of paper to begin with or digitally, and are sometimes made of sturdier materials like paperboard or cardboard if they need to be more robust to withstand repeated use.
Production is the process of manufacturing the final product in multiples, based on an order placed by the buyer. Usually, production takes place after Minimum order quantity requirements are met and sample approved and prices agreed.