[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],[],[],[],null,["# Concepts\n\nWeb Risk Overview\n-----------------\n\n- [### Web Risk overview\n An introduction to Web Risk.](/web-risk/docs/overview)\n- [### Local databases\n Set up a local database and perform an initial download of the lists you want to work with.](/web-risk/docs/local-databases)\n- [### Update constraints\n Specify size constraints when updating local databases.](/web-risk/docs/update-constraints)\n- [### Caching\n Use the Lookup API and the Update API to create and maintain a local cache of threat data.](/web-risk/docs/caching)\n- [### Compression\n Use compression to reduces bandwidth requirements, which is particularly, but not exclusively, relevant for mobile devices.](/web-risk/docs/update-constraints)\n- [### Request frequency\n Explore how the Update API imposes time intervals for how often a client can send requests to the Web Risk server to perform URL checks or to update the local database.](/web-risk/docs/request-frequency)\n- [### Lists\n Learn about how Web Risk lists, also referred to as threat lists or simply lists, are Google's constantly updated lists of unsafe web resources.](/web-risk/docs/lists)\n- [### Status codes\n Learn about the HTTP status codes the server can generate in response to a request.](/web-risk/docs/status-codes)\n- [### User warnings\n Learn how to warn users about potential risks.](/web-risk/docs/user-warnings)"]]
