What's the point of partitioning?

[default settings]

Please excuse my ignorance, I don't know much about computers.
I have Windows 7. All of my computer's files go into C:, while D: remains empty. What's the point of drive D:? Why didn't my memory come united under one, large drive instead of two separate ones?

 

[MyCattMaxx]

I use partitions for several reasons:
1. My main reason is to have a storage partition to keep things I want to save.
I reformat a couple of times a year and it saves time from moving the data over.

2. Some of my comps are dual boot so I need a partition for the second OS.

 

[strollin]

It's largely a matter of preference. You can use partitioning software such as Partition Master 9.2.2 Free Edition to shrink the D: partition, then enlarge the C: partition if you wish.

You could use your D: drive as is to keep your data separate from your OS. Just remember to navigate to a folder on the D: drive when saving your data files.

 

[jamesd1981]

People partition for many reasons depending on their use, some people have lots of separate partitions.

The most common reason is to have a separate partition to store your personal files, because if you keep your personal files in your windows partition, if you ever get a virus or re-format without thinking you will lose all your personal files.

Some people also use a separate partition to install software and games.