Star Seeds are incarnated souls who originate from other planets or stars.
Star Seeds have often had few or no previous lifetimes on earth. They are attracted to Earth and humanity at this time of Ascension as it is easier for them to integrate with humanity now than at previous times. They also have many important gifts for humanity and roles to play in this time of great change for humanity. Their energy fields are quite pure and expansive as they have not been experienced the process of become dense through living on earth before. Even thought they have amazing gifts, they can find it hard to integrate within humanity which is so different from the Star Beings and worlds that they represent. They simply have no experience of the lower consciousness of humanity.
The New Star Seeds are often young and some see them as Crystal and Rainbow Children. Some are the Seeds of Ashtar. This lifetime is often the beginning of future cycles of lifetimes on Earth and so they are preparing for future lives and future missions in this lifetime.
The motivations for all Starseeds to come to Earth are to help and serve mankind as well as planet Earth. These beings very often have gifts to share with others such as in the areas of healing, channeling and spiritual education.There is a strong desire in Star Seeds to help others and usually there is a plan made prior to birth as to how this may be manifested and expressed when they become a human being. The details of this plan are called the Life Missions and represent potentials for individual Star Seeds and not certain destinies.
Lightworkers are people who have chosen to do their part to assist Earth and Mankind in their ascension. Lightworker is a term given to those who are actively on the spiritual path. Not all Lightworkers are starseeds or walk-ins, and star-seeds and walk-ins only become Lightworkers when they have made the conscious choice to begin their spiritual path and assist others.
Ref: Internet and my own guidance and experiences.