A friendship bracelet is a decorative bracelet given by one person to another as a symbol of friendship. Friendship bracelets are often handmade, usually of embroidery floss or thread and are a type of macrame. There are various styles and patterns, but most are based on the same simple half-hitch knot. They resemble a friendship that is strong and everlasting. If one were to remove the bracelet it resembles that the friendship has ended. (over) The only proper way for a bracelet to come off is by natural wear and tear and to eventually fray enough to fall of.

The amount of thread used in bracelets varies depending on the pattern. The smallest pattern, a double chain knot, requires two strings while the candy stripe can have 3 or more strings depending on the desired thickness.

More Info: en.wikipedia.org