What are workflows?
Workflow is the automated movement of documents or items through a sequence of actions or tasks that are related to a business process. Workflows can be used to consistently manage common business processes within an organization by enabling the organization to attach business logic to documents or items in a SharePoint list or library. Business logic is basically a set of instructions that specifies and controls the actions that happen to a document or item.
Why use SharePoint Workflows?
Workflows can streamline the cost and time required to coordinate common business processes, such as project approval or document review, by managing and tracking the human tasks involved with these processes. You can add a workflow to a document library that routes a document to a group of people for approval. When the document author starts this workflow on a document in that library, the workflow creates document approval tasks, assigns these tasks to the workflow participants, and then sends e-mail alerts to the participants with task instructions and a link to the document to be approved. While the workflow is in progress, the workflow owner or the workflow participants can check the Workflow Status page to see which participants have completed their workflow tasks. When the workflow participants complete their workflow tasks, the workflow ends, and the workflow owner is automatically notified that the workflow has completed.