准备 (zhǔnbèi) means 'to prepare' (concrete actions like cooking or studying) or 'to intend' (a plan). 打算 (dǎsuàn) is only about intending/planning, not the hands-on preparation. 预备 (yùbèi) is more formal and often used for advance preparation, while 筹备 (chóubèi) is for large-scale events or projects.