Obtaining a Quality assurance certification is one way of expanding your QA knowledge base and expertise.
If you decide to get a Quality assurance certification, you may want to think about focusing on a particular discipline. Some people look to broaden their experience and expertise by obtaining certifications in multiple areas (i.e. quality assurance and quality control certifications).
Another option is to focus on one aspect of quality assurance. For instance, you may decide that you want to pursue a career as a quality assurance analyst, perhaps with a path to management. If you are new to the job, you may initially choose a QA certification such as Certified Associate in Software Quality. Once you have some experience and the appropriate skill level, you can continue along that path and obtain a Certified Software Quality Analyst certification, and ultimately a Certified Manager of Software Quality certification.
If you decide to focus on Quality Control, you can obtain certifications such as Certified Associate in Software Testing, followed by Certified Software Tester, and Certified Manager of Software Testing if you decide to follow the management path.
In addition to what I think of as the “mainline” or traditional Quality assurance certification categories, you can obtain certifications in related disciplines, such as project management, business analysis, and process engineering.