Through phishing online scammers send emails in which they attempt to sensitive personal information such as passwords or account information. Pay attention to the email address from which a message is sent and be cautious about any email from an unfamiliar email address, particularly if they include links or attachments or ask you to provide sensitive information. See these resources for more on avoiding phishing scams:
Web 2.0 and the proliferation of social media has increasingly blended our online life into our life IRL to the point that it is almost meaningless to differentiate between the two. Online harassment includes, but is not limited to, doxing, threats, denial of service attacks, "revenge porn" and non-consensual sexual image sharing. The resources below will help you protect yourself from online harassment, as well as your digital privacy in general.