Quoted from the official source:
Micro-Certifications What are Micro-Certifications and how can I register for them? These are smaller certifications than mainline certifications that are targeted for specialty products or topics. Unlike mainline certification exams, these are non-proctored exams that do not require visiting a testing center. Like the mainline certifications, there is always paired training content that must be completed before attempting a micro-certification exam, however these are often available as shorter, self-paced modules.
