Skills such as taking a first step, smiling for the first time, and waving "bye-bye" are called developmental milestones. Developmental milestones are things most children can do by a certain age. Children reach milestones in how they play, learn, speak, behave, and move (like crawling, walking, or jumping). During the second year, toddlers are moving around more, and are aware of themselves and their surroundings. Their desire to explore new objects and people also is increasing. During this stage, toddlers will show greater independence; begin to show defiant behavior; recognize themselves in pictures or a mirror; and imitate the behavior of others, especially adults and older children.
Toddlers also should be able to recognize the names of familiar people and objects, form simple phrases and sentences, and follow simple instructions and directions.