Creating a Job Alert helps you find access to the latest jobs matching your aspirations. Based on the criteria that you have specified for your Job Alert, you get latest matching jobs in your inbox. You can create up to 5 personalized Job Alerts, each with different criteria. 
To use the benefits of Job Alert, it is not necessary for you to be registered on the site. Creating a Job Alert, thus, helps you access latest job vacancies based on your job requirements.