Three tools sit on a docent’s bench: one reads a whole plaque and labels it, one writes the next sentence of a story, and one reads a source language then writes a target language. Which architecture families are those?

Three benches, three jobs. Encoder-only reads both ways and labels. Decoder-only writes the next sentence. Encoder-decoder reads one language and writes another. Swap those families, or call them graph or NCCL tools, and the plaque, the story, and the translation all land on the wrong bench.