About trailing stop

can anyone guide me about trailing stop. what is trailing stop. and how can we use trailing stop in trading?

as instaforex me ham jo traling stop use karte hen pairs me woh kam se kam 15 points tak rakh skate hen or agar ham ne maximum gain karna he toh ham iska use kar skakte hen is se hamko jese he 15 pips profit hua toh traing hit hoga or jese jese profit increase ho ga toh trailing be move hota jay ga

apne ek kafi ahem sawal uthaya hai mere dost is k baray me main bhi janna chahta hun kyun k mene abhi in cheezo pe kam nahi kiya hai lehaza hume in cheezo k bare me seniors say opinion leni chahye.............

gee bhai trailing stop ka istemal trader ko boht faida deta he is ke istemal se trader apne profit ko mahfooz kr skta he aur trader ko chahe apne trading mein acha profit hasil krne ke lie trailing stop ka istemal kre phr trading se profit acha ho jata he