In literary analysis, what does synecdoche specifically refer to?

Synecdoche specifically refers to the use of a part of something to represent the whole. This literary device is commonly employed to create a more vivid or relatable image in the reader's mind. For example, when we say "all hands on deck," we are not just referring to the physical hands but to all the people on the ship. By highlighting just a part (the hands), it conveys a larger concept (the crew members) effectively. This technique is powerful in both poetry and prose because it engages the reader's imagination and encourages deeper connections with the text.