Thank you for the opportunity to help you with your question!
difference between the 3 and 5 years physically is that the three year old can not learn as fast as the five year old who has the ability to do everything by themselves. the three years old is starting to learn their mother tongue while the 5 years old has already learned the language and is exercising, emotional development of the of the 5 years old has developed in a great deal and can be able to control themselves
the difference between a toddler and an infant physically is that the the infant has yet to adapt to the environment where they are born unlike the toddler who can even crawl, the infant has not developed speech because they can not even ulter a single word by themselves while the toddler can at least utter some words, the infant can not differenciate what is wromg and what is right so they have not developed their emotions unlike the toddler who is in the process of learning
Please let me know if you need any clarification. I'm always happy to answer your questions.
Content will be erased after question is completed.