English Sign Language
American Sign Language (ASL) and Signed English (SE) are used to communicate with deaf people. The basic signs for words are the same; however, with Signed English (SE) a sign is executed for every word in a sentence whereas American Sign Language seeks to cover a concept with each gesture. For example, if I were to sign "I have two sisters" in Signed English, I would make a sign for each word. In ASL, I might make the signs for "two" and "sister" and then point to myself, conveying the thought "two sisters, me".Some people have described ASL and other sign languages as "gestural" languages. This is not absolutely correct because hand gestures are only one component of ASL. Facial features such as eyebrow motion and lip-mouth movements are also significant in ASL as they form a crucial part of the grammatical system. In addition, ASL makes use of the space surrounding the signer to describe places and persons that are not present.
There is no "universal sign language" or real "international sign language." There is a sign form called Gestuno that was developed by a committee of the World Federation of the Deaf. It's not really a language, more a vocabulary of signs that they all agree to use at international meetings. But no one really signs Gestuno as a native language, just as no one really uses Esperanto as their native spoken language.