Final answer:
A Massive Open Online Course (MOOC) is a form of external training that aligns with the trend of adults engaging in continuing education, accessible globally via the internet.
Step-by-step explanation:
A Massive Open Online Course (MOOC) is an example of external training. This type of training is generally operated by external organizations rather than by an internal staff within a company. MOOCs offer a platform where participants, often adults, can engage in continuing education to acquire new skills or enhance their knowledge in a specific field. These courses are delivered over the internet, allowing for a broad and often global audience to participate. They align with the current trend where adults are increasingly participating in continuing education, made accessible through their employers, colleges, and universities.