As per wiki, bcrypt is a password hashing function designed by Niels Provos and David Mazières, based on the Blowfish cipher. Bcrypt uses adaptive hash algorithm to store password.BCrypt internally generates a random salt while encoding passwords and hence it is obvious to get different encoded results for the same string. But one common thing is that everytime it generates a String of length 60.
For bcrypt encryption, first enter the plain text that you want to encrypt. It can be any plain text. Now select the salt round. Salt round represents the cost factor and cost factor is directly propotional to amount of time needed to calculate a single BCrypt hash.Now you can submit the form to generate the bcrypt hash online for the plain text that you have entered.
Similarly, to match a hashed password you require to provide the hashed password and the plain text to match with. Doing so the tool will compare the both inputs and give result whether the hashed password and plain text matched or not as true and false.