> While we can use pretrained models such as Word2Vec to generate embeddings for machine learning models, LLMs commonly produce their own embeddings that are part of the input layer and are updated during training.

So out of interest: During inference, the embedding is simply a lookup table "token ID -> embedding vector". Mathematically, you could represent this as encoding the token ID as a (very very long) one-hot vector, then passing that through a linear layer to get the embedding vector. The linear layer would contain exactly the information from the lookup table.

My question: Is this also how the embeddings are trained? I.e. just treat them as a linear layer and include them in the normal backpropagation of the model?