“身份证”的翻译是identification card还是identity card

两者都可以，均通常略作ID card。如 Oxford American Dictionary for Learners of English 对 ID card 的解释是：a card with a person’s name, date of birth, photograph, etc. on it that proves who he / she is. ID card is short for “identification card” or  “identity card.”

例句：

identification card

He flashed his identification card. 他亮了一下自己的身份证。

She showed her identification card and teas let in. 她出示了自己的身份证便被放行了。

identity card

The identity cards are examined by an electronic scanner. 用电子扫描器来检验身份证。

Everyone has to show their identity cards at the entrance to the building. 在大楼的入口，每个人都必须出示身份证。

 ID card

An alarm salesperson should show an ID card. 报警器销售员应出示身份证。

Registrars checked the ID cards of prospective voters.  登记员核对未来投票人的身份证。