A professional learning network (PLN) is a dynamic and personalized ecosystem of people, spaces, and tools that support an educator's ongoing career-based learning. PLNs are not limited to a single platform or modality, but rather encompass multiple spaces and modalities, such as conferences, workshops, webinars, Twitter chats, unconferences, Reddit forums, and massive open online courses (MOOCs). The people within a PLN provide career-based feedback, advice, ideas, emotional support, and mentoring, while the spaces and tools offer opportunities for professional knowledge building with and from others.

The concept of PLNs has evolved over time, with Tobin (2000) being one of the first to highlight the importance of building a "personal learning network." However, the terms "personal learning network" and "professional learning network" are often used interchangeably, with the latter preferred when referring to career-based learning.

PLNs offer several benefits, including informal, self-directed, and interest-driven learning experiences that can happen anytime and from anywhere. Educators can choose which people, spaces, and tools support their unique needs, interests, and goals, and they can shift and evolve their PLNs over time based on changing professional needs, interests, goals, and broader contexts.

While PLNs offer numerous benefits, there are also challenges associated with their use, such as the potential for miseducation, distraction, and echo chambers. Educators must critically reflect upon their PLNs, the information exchanged, and the way their PLNs influence them. Tools such as the PLN Enrichment Framework can support this reflection process by providing a heuristic for interrogating the people, spaces, and tools within a PLN.

Related terms include personal learning network, informal learning, personal learning environment, self-directed learning, and MOOCs. Community artifacts, such as watch parties on YouTube, can also be used to support PLNs.