How do databases work?

Databases are designed to make work task more efficient. A database stores information such as names, addresses, age, etc. in separate fields to allow other programs to call up these fields when needed. For example, if I wanted a list of all size 10 women shoes I could have a database of different sized shoes but I'm only looking for women size 10. Hence, my database would produce only the size 10 women shoes for my needs. All the other sizes would not show up. It's like a storage of information and you only pull up what you need. This is basically how a database works.