Shop drawings come after award. They are a type of submittal. The architect reviews them against the design intent before fabrication starts.
A steel fabricator draws every beam and connection. A casework shop draws each cabinet run. A gym equipment supplier draws backstop locations and attachment to structure.
Shop drawings cost time and money. Read your spec section for what it requires. Some sections ask for engineered and stamped drawings.
Carry the drafting cost and the review time in your bid. Review time also affects lead time for fabricated items.