A Slack channel is a dedicated space for chat, sharing files, and video/audio calls within a workspace. To create a new channel, click "Channels" > "Create" > "Create channel", enter the name, set visibility (public or private), and optionally invite members or guests. Channel management involves renaming, joining, grouping into sections, leaving, muting, deleting, archiving, and removing members. Automating Slack with Zapier can enhance productivity by automating tasks and integrating with other tools.