In computing, an address space defines a range of discrete addresses, each of which may correspond to a physical or virtual memory register, a network host, peripheral device, disk sector or other logical or physical entity.
A memory address identifies a physical location in computer memory, somewhat similar to a street address in a town.
The address points to the location where data is stored, just like your address points to where you live.
In the analogy of a person's address, the address space would be an area of locations, such as a neighborhood, town, city, or country.
Two addresses may be numerically the same but refer to different locations, if they belong to different address spaces.
This is similar to your address being, say, "32, Main Street", while another person may reside in "32, Main Street" in a different town from yours.
Read the rest of the article here