There are many different types of back pain, here are a few of them:

Acute or Chronic
There is a distinct difference between acute pain and chronic pain. Acute pain is a way in which your body warns you about sources of harm and tells you to protect yourself while the body heals.

Cronic pain lasts much longer but can be just as unpleasant. It is usually classed as chronic when it lasts for 12 weeks or more.

Disc Problems
Disk problems are uncommon and never the result of slipping a disk. Usually the disk has torn or become distorted, so it presses against sensitive nerves from the spinal cord. 

Sciatica 
Sciatica is the name given to pain that runs down the leg caused by the nerve from the spinal cordbeing pinched or irritated by damage to the back.

Osteoarthritis
This is a long term degeneration of the joints, which makes then less able to withstand physical stress.

Facet Joint Problems
Spine movement is made possible by joints between the vertebrae consisting of two flat faces, or facets, on the bone. If these degenerate, the two halves of the joint grate against each other, causing inflamation and pain.

Osteoporosis
This causes weakness in the bones, so that they fracture easily. It is common in post-menopausal woman and can be influeced by stopping smoking, diet, calcium, vitamin D suppliments and activity.

Diseases
Some diseases contribute to back pain and are likely to need long term treatment. These are far less common than minor damage to the backs muscles.

Inflammatory Joint Diseases.
Many inflammatory diseases such as Rheumatoid Arthritis cause the joints to become inflammed and seize up. This can directly affect the joints or cause problems with other joints that lead to pain in the back.