A more thorough explanation:

A general warrant is a type of warrant that gives a law-enforcement officer broad authority to search and seize unspecified places or persons. It is a search or arrest warrant that lacks a sufficiently particularized description of the person or thing to be seized or the place to be searched. General warrants are unconstitutional because they fail to meet the Fourth Amendment's specificity requirements.

For example, a general warrant might authorize a police officer to search any house in a particular neighborhood without specifying which house or what they are looking for. This type of warrant is illegal because it violates the Fourth Amendment's requirement that warrants be based on probable cause and describe with particularity the place to be searched and the things to be seized.

General warrants were banned by Parliament in 1766 after they were used by the English Secretary of State to arrest the author, printer, or publisher of a seditious libel without naming the persons to be arrested. The practice of issuing general warrants continued in the United States until the landmark case of Money v. Leach in 1763, in which the warrant was declared void by the whole court of king's bench.