This is a good overview of common job titles and responsibilities in the GIS field, along with rough guidelines for the amount of experience required for each.
The use of geospatial technologies is increasingly being used in a variety of fields. GIS is being used in many different industries and the skills required to be a successful GIS professional have evolved over the years. Below are recommendations on building a strong background in preparation for a career in GIS based on what the majority of employers are looking for.