Digests are short summaries of decisions, highlighting key facts and legal issues. In addition to allowing you to quickly scan a significant volume of decisions, digests are also usually organized topically, in a tree structure that allows you to browse to a fairly refined subset of digests.
The Canada Digest is available on Lexis+ (Content Type - Cases - Case Summaries - All Canada Digests), "a collection of over one million relevant and leading English and French-language case summaries divided up by area of law and topic." With over 50 major topics, most areas of law are covered. Each topic has its own update schedule and coverage, with most topics covering back to the mid 1800s (for example, Canada Legal Profession Digest has "coverage starts February 24, 1871", whereas Canadian Labour Arbitration Digest has "coverage from 05 January 1949 through current").
The Canadian Abridgement (Westlaw Edge Canada) "[c]overs virtually every case reported in Canada since 1803, and every reported or unreported case received from the courts since 1986, with the exception of Quebec civil law cases" and purports to classify essentially every court case available on Westlaw Edge Canada. Like every source on Westlaw, the Abridgement can be searched at any level during the browsing process. However, it is important to understand that this search only searches the digests at the selected level, not the full text of the digested cases.