Trademark protects identifiers (logos, names, slogans, etc.) that are used to identify the source of a commercial good or service. They are administered by the USPTO and they last as long as they remain in active use.
Trade Secrets protect secret information, often information that isn't patentable or is too sensitive to patent. They only last as long as they're secret, and are protected by legal documents like non-disclosure agreements.
The new (as of 2022) patent search tool from the USPTO. It covers US granted patents and patent applications from 1836 to present, although older patents have fewer searchable pieces of information. This replaces the PatFT, AppFT, PubEAST, and PubWEST search tools.
This database features Google's easy-to-use search interface, but Google's search algorithm can be inconsistent when dealing with legal-technical patent language. You can use it for doing a first pass when patentability searching, but make sure to use other resources as well.
This database covers international patents and rewrites the titles in easier-to-read language. Most topics go back to the 1960s. Chemical structure searching is available. This is a subscription database for Purdue users, and not open to the general public. Derwent is recommended for researchers and students, but is not the best choice for a formal patentability search.
NexisUni features more than 15,000 news, business and legal sources from LexisNexis—including U.S. Supreme Court decisions dating back to 1790—with an interface that offers discovery across all content types, personalization features such as alerts and saved searches, and a collaborative workspace with shared folders and annotated documents. NexisUni's patents content can be found using the "Menu" dropdown at the top of the homepage. Their patent coverage focuses on US, EU, Great Britain, Japan, and WIPO documents.
This European Patent Office (EPO) database has international coverage and includes an excellent Cooperative Patent Classifcation (CPC) search tool. Patent information is provided by more than 82 patent-granting organizations. Machine translations are available for many languages. Espacenet also does an excellent job of making connections between patent filings in different countries, identifying "patent families" that share claims.
PAIR is a tool for finding public, but not easily accessible, information about patents and patent applications. You can see all of the legal filings, supporting documents, and correspondence between an inventor and a patent examiner for a given document.