Difference between Bie de and qi ta

Hi I'm doing the Chapter 4 of chinese rocket language, and I saw that they used "bie de" and "qi ta" to both mean other.  If someone could explain what the difference is I would greatly appreciate it.

According to my local expert, bié de  and qí tā de are equivalent and can be used interchangeably.  Notice, both now have the "de", which would allow an object to be referenced.  For example, qí tā de rén means "other people or other person".  Sometimes the "de" is omitted.

Nǐ hái xiǎng diǎn shénme qítā de cài?

A literal translation of the above sentence from 4.2 could be: " You still want to order what other dish?"