Hello ticklishLaugh,
Happy to answer your question. Everyone needs to ask questions the first time, after all, we all didn't know the answer to this one at some point. Thanks for not being afraid to ask.
Bondage is the art of physical restraint . It involves having a partner (or several) to bind, and something to do it with.
Once can use rope, cuffs, chain, leather, saran wrap, and dozens of other things to accomplish it.
This practice is a fetish unto itself, and can cover many forms and areas. People do it for a number of reasons. Some enjoy the look of a bound partner. Others like having a helpless partner so they can do what they like to them (A tickler for instance) Some people feel very safe and secure when bound. There are as many reasons as there are people, just like in the tickling fetish.
Hope this helps, and feel free to ask other questions, or more on this if need be.
Myriads