You can find the website at http://www.jobbank.gc.ca/home-eng.do?lang=eng
From their About Us page:
Job Bank is the Government of Canada's leading source for jobs and labour market information. It offers users free occupational and career information such as job opportunities, educational requirements, main duties, wage rates and salaries, current employment trends, and outlooks.
The site can help people search for work, make career decisions, see what jobs will be in demand, and much more. Employers can also advertise jobs for free.
Job Seeker is just an online account for Job Seekers -- allowing you to search jobs, find matches, update your resume, etc. Create an account starting on this page.
However, it appears that some aspects of the Job Seeker account have been retired and are being replaced next year from this page:
A new Job Match Service - Coming Soon!
Registration for a new Job Match Service will begin in 2015.
Job Match allows employers and job seekers to be matched based on their respective needs and profiles. After being matched, the employer receives a list of qualified candidates while the job seeker receives a list of matching job openings.
But it still looks like you can do normal job searches and use the other tools.