in general, Crowdsourcing describes the processes for delegating a task or challenge to a broad, distributed set of people using the Web and social collaboration techniques. for instance: Freelance.com and Upwork  instead of performing this job through a designated employee,

Crowdsourcing applications typically include mechanisms to attract the desired participants, stimulate relevant contributions and select winning ideas or solutions.

but this process, has its drawbacks as the accuracy will always be a matter of question as you are not sure how professional is the one who is responsible for the job>

Elearning role in harnessing crowdsourcing:

However, in the e-Learning model, the Requestor is the student, who searches (and pays) for the knowledge-related service. The Provider is usually an Education Institution, paid to teach and certify the student. In this e-Learning model, there are few Providers and a crowd of Requestors, the opposite of the usual setup. Some e-Learning tools use another way to spread knowledge: they use the crowd itself as provider. In this fully collaborative environment, the role of a person varies according to their actions in the crowdsourcing tool, being a Requestor (student), a Provider (tutor/teacher), or both at the same time (but in different topics of study)

references:

Definition of Crowdsourcing - Gartner Information Technology Glossary

What is Crowdsourcing? - YouTube

(PDF) Crowdsourcing Environments in E-Learning Scenario: A Classification Based on Educational and Collaboration Criteria (researchgate.net)