Whatever actions are necessary to carry out the intent of statutes; those acts required by legislative policy as it is expressed in laws enacted by the legislature.
If a city commission votes to create the position of park superintendent, that is a legislative act that can take effect only if the commission follows all the steps required for formal legislation. When the same commission votes to rezone a parcel of real property from single-family residential to business uses, however, that is an administrative act that does not require the same formality as legislation. It is administrative because it is carrying out the zoning laws already in effect.
"Administrative Acts." West's Encyclopedia of American Law. . Encyclopedia.com. (September 23, 2018). http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/administrative-acts
"Administrative Acts." West's Encyclopedia of American Law. . Retrieved September 23, 2018 from Encyclopedia.com: http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/administrative-acts