Install wodim; its name is derived from Write data to Optical DIsk Media. This utility has many options; in a simple setup it figures out what you want to do and does it.
To burn an ISO image file, first determine the device name of the CD/DVD:
$ wodim --devices
wodim: Overview of accessible drives (1 found) :
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0 dev='/dev/scd0' rwrw-- : '_NEC' 'DVD_RW ND-2510A'
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Then, burn ISO image file:
$ wodim dev=/dev/scd0 -v -data name.of.file.iso
Replace -data with -audio to burn .wav files. That’s it!