There are three types of racket strings you can get:
Nylon
Gut
Synthetic gut.
Nylon is pretty durable and cheap, but it tends to lose tension before it snaps.
Gut is by large the choice of many professionals, but it is fairly expensive and commonly not recommended except if you can afford to purchase in bulk and own a stringing machine. Strings from gut are resilient and hold tension better. Most players also like the feel better. On the other hand, humidity affects gut strings and causes them to degrade. Gut strings don't last as long as nylon.
The compromise can be synthetic strings. Mostly, gut is made by strands of sheep or cow gut, and it is twisted much like string or twine is made. To achieve this effect, synthetic gut does pretty much same things with nylon strings. Synthetic gut costs is more expensive than nylon but is cheaper than real gut. These strings feel and hold tension much better than nylon.
Synthetic strings can be of three basic types: multifilaments, monofilaments, and aramids.
The prices on strings range from around US $15-$22 for nylon strings to US $15-$30 for synthetic gut and to US $25-$55 for gut strings. Strings can be acquired in larger reels for home stringing for less.
The basic string facts have been compiled in the list below:
1. Lesser string tensions produce more power.
2. High string tensions provide advanced ball control.
3. Longer length of the strings generates more power.
4. Lower string density produces more power.
5. Thinner strings generate more power
6. More resilient strings produce more power (in general, basic string facts show that what generates more power also absorbs more shock load during a shot).
7. Strings with softer coating, or softer strings have a tendency to vibrate less.
8. Thinner strings have tendency to generate more spin.
9. Lower string density (less number of strings) produces more spin.
10. Multifilament racket strings are more resilient than solid core ones.
11. Longer strings on the string bed are in motion more that's why break easier.
12. Solid core strings tend to be more durable than the multifilament strings.
13. Kevlar racket strings are the least flexible and stiffest.
14. Multifilament strings feel better during a play than solid core strings.
15. Multifilament strings tend to lose tension quicker than center core strings.
16. Textured strings are likely to generate more spin.
17. Gut strings tend to hold tension the best.
18. It is one of the acknowledged basic string facts that gut strings are the most flimsy strings.
We have ended up with basic string facts and now let's switch to the important question of racket restringing. Restringing should be done as regularly as you play tennis for example, each week, or minimum once a year. For instance, play tennis as regularly as three times a week; you ought to restring your racket minimum three times a year. Keep in mind that high string tension produces more control and less power; and vice versa, low tension on strings generates less control and more power.