Children change rapidly during their first year of life. Significant stages of development during this period are called milestones. The exact age at which each child reaches their milestones varies slightly, but these developmental milestones help serve as a guide.
In this way, milestones can help you better understand when to expect certain behavioral and physical milestones. Like smiling, laughter is another way your child communicates with you. Every new sound your child makes comes from learning mouth and tongue movements, so like any new skill, laughter takes some practice.
It is important to remember that children reach their milestones at different times. While charts are a great reference tool, you may find that your child is picking up some skills sooner or later than expected. Milestones are grades and there is a range of normal values for when a child achieves significant milestones.