1.身份证 is a term with only one meaning:Identification Card. But 证件 can refer to ID card,driver's license,student card,passport,etc. 2.dei3 dao4 is rcorrect. When the word's(得) pronunciation is "dei3",it means something/someone need/must......it's very similar to the term"需要" in Chinese. Hope it is helpful.

There are many证件,身份证is one of them, 得到，这个读dei3 dao4

证件：是一个总的称呼。身分类证件包括：身份证、学生证、军官证、护照。其他证件包括：驾驶证、工作证、毕业证等等。 得到，这个读dei3 dao4。例句：如果你的身份证丢失，你/得到/得去/派出所才能补办。（得到是必须去到的意思）

身份證 usually means a Chinese ID card that every single Chinese national has. It's like an ID card, you need it to take trains and stuff in China. 證件 just means documents or papers, one that can verify your identity. The word 證件 can be a work pass for getting into your office, your student ID card, your passport, a 身份證 is a type of 證件, a driving licence or even a graduation certificate. Laurence