To understand what it means, you need to know the entire sign and the context it's used in. For example:
* "I": Touching the palm of the dominant hand with the index finger of the non-dominant hand is a common sign for "I".
* "You": Touching the palm of the dominant hand with the index finger of the non-dominant hand, but pointing it outwards, can signify "you".
* "Deaf": Touching the palm of the dominant hand with the index finger of the non-dominant hand while rotating the hand outward signifies "deaf".
In short, touching the palm is a component of many signs, and its meaning varies depending on the sign and context.
It's important to remember that sign language is a visual language, and subtle changes in handshape, movement, and location can change the meaning completely.