Spatial awareness is how children themselves to the environment around them. More so than just being aware of other people and things, it is the ability to understand where those things are in relation to oneself. Spatial awareness is one aspect of overall perception.
Before children can begin to understand the concepts of distance, time, speed or depth, they must first learn to understand how other things within the realm of their environment affects their ability to move or position themselves so as to be least disruptive to those things around them. This can involve seemingly small details, like learning not to stand too close to others or knowing at what point to kick in order to make contact with a ball or larger details such as understanding left from right and up from down. The development of proper spatial awareness involves an understand of how the human body moves and the basic functions of its parts. Babies have little spatial awareness for this reason, though it is thought that everyone is born with a certain amount of innate spatial awareness. This is why infants tend to frequently bump their heads or roll off elevated surfaces such as sofas if left unsupervised.