Legislation is the product of the Legislative Branch of the government. It can be thought of as "the rules," which are then interpreted and applied by the independent Judiciary Branch. "Legislation" is actually a broad term, inclusive of both statutes and regulations, at the Federal level. Legislation can be seen as working in concert with caselaw, with each being shaped and influenced by the other, and neither standing independently.
The most common legislative tasks include:
While there are some very technical differences between a statute and an act, for legal research and understanding purposes, "act" and "statute" can be treated as synonyms. Statutes/act are pieces of legislation passed by the legislature of the jurisdiction in question. Federally, this would be House of Commons and Senate.
Regulations are subordinate or delegated legislation. Every regulation is authorized by, and "belongs to" or is made under a statute. Regulations tend to encompass the practical aspects or application of an act, and often take the form of lists, charts, tables, or even images (street signs being a classic example of the latter). Think of the relationship between act and regulation as the act setting out what can be included in a regulation: An act may permit regulations concerning, for example, what food additives are permitted. The regulation will contain the actual detailed list of these additives. The advantage of this system is that if this content was in the act, any changes to it (addition or deletion of additives, in our example) would require the entire three reading legislative process, which would be impossibly unwieldy, while the regulation can simply be amended by a new regulation in the Gazette.