Stamp 1 is a granted immigration permission that allows you to work and live in Ireland as employed, self employed or as a business owner.
Stamp 1A specifically applies to those who are training to become an accredited accountant in Ireland.
Stamp 1H specifically applies to those who wish to work as a Non Consultant Hospital Doctor (NHCD) in public Irish hospitals or healthcare facilities on a two year General Employment Permit.
Stamp 1G specifically applies to graduate students from a foreign or Irish university who currently hold Stamp 2, and who have received permission to search for employment opportunities in Ireland under the Third Level Graduate Programme.