問60
頻出度★★★
“http://example.co.jp/index.html” で示されるURLのトップレベルドメイン (TLD) はどれか。
平成27年度 春期 ITパスポート試験 問60
テクノロジ系ネットワーク › ネットワーク応用
This question's explanation and your answers so far.
解説
問 60
Incorrectア
http is the scheme (protocol) name placed before «://», and it is not part of the domain name. It indicates the communication protocol used to retrieve a web page, so it is not a TLD.
Incorrectイ
example is the leftmost label of example.co.jp and is the lowest-level part, registered by each organization (a company or other body). It is a third-level label placed under co.jp, so it is not the highest level.
Incorrectウ
co is one level below jp, that is, a second-level domain, and it is an attribute-type label indicating a company in Japan. The level above it is jp on its right, so co itself is not the top level.
- エ
正解 A URL has the structure «scheme://host name/path». In “http://example.co.jp/index.html”, http is the scheme (the communication protocol), example.co.jp is the host name (domain name), and /index.html is the path (the location of the file). A domain name is a hierarchy separated by dots, and the further right a label is, the higher its level. Here the order from higher to lower is jp → co → example, so the highest level, that is the top-level domain (TLD), is the rightmost label «jp». jp is the country code top-level domain (ccTLD) for Japan, so the correct answer is エ.
ここがポイント
- Structure of a URL: read it by breaking it into «scheme (http) :// host name (domain name) / path».
- A domain name is a dot-separated hierarchy, and the rightmost label is the highest level (the top-level domain). There are country code TLDs (ccTLDs) such as jp and us, and generic TLDs (gTLDs) such as com and org.
用語