PIPEDA is based on balancing an individual's right to the privacy of personal information with the need of organizations to collect, use or disclose personal information for legitimate business purposes. The Act also established the Privacy Commissioner of Canada as the ombudsman for privacy complaints.
Remember: PIPEDA, unlike the Privacy Act, applies to the Canadian private sector! PIPEDA applies to organizations who collect, use or disclose personal information in the course of commercial activities.
This Act is divided into five parts. Part One outlines the ground rules for managing personal information in the private sector. Parts Two through Five concern the use of electronic documents and signatures as legal alternatives to original documents and signatures.
PIPEDA is a consent-based Act, meaning that you must have consent to collect, use or disclose information. The Privacy Act is authority-based, meaning that you must ensure that you have the legal authority to collect, use or disclose information.

The Act is being released in a series of stages, each corresponding with what the Act will cover in terms of personal information. Stage One began in January, 2001. Stage Two began January 1, 2002 and the final stage occurs on January 1, 2004.
For more information on what is being covered in each of these stages with respect to personal information click here.

"substantially similar"
"to be considered substantially similar, any provincial legislation will have to contain, at a minimum, the 10 principles set forth in Schedule 1 to the Personal Information Protection and Electronics Act [Universal Principles]". Source
Industry Canada has issued a statement on how the Governor in Council will decide whether a provincial law is substantially similar to provincial law - Canada Gazette Part I, Sept. 22, 2001, p. 3618
Part 2 of PIPEDA deals with Electronic Documents. It provides a framework by which federal statutes and regulations may be adjusted to accommodate electronic alternatives to paper-based means of communication. For some types of documents, such as those that must be signed under oath, witnessed or sealed, only a Secure Electronic Signature is appropriate.