25 side-by-side comparisons of the concepts interviewers ask about most. Understand the tradeoffs, know when to use what, and never confuse the two again.
BPE merges frequent pairs, WordPiece picks merges by likelihood, SentencePiece is a training framework that treats input as raw bytes (or unicode) and can produce BPE or unigram tokenizers.
CoT reasons in a line; ToT explores multiple branches, evaluates them, and keeps the promising ones. ToT costs many more tokens but wins on hard search problems like puzzles.
Zero-shot asks the model to do a task cold; few-shot shows examples; chain-of-thought asks the model to reason step by step. They compose: few-shot chain-of-thought is often stronger than either alone.