bare-bones

Short definition from Wiktionary

Adjective

1. 1
   Minimalist; lacking that which is not essential.
2. 2
   Describes a computer sold preassembled, but without certain essential components, often a processor, memory, and hard drive.

Noun

1. 1
   The essential elements of something; the minimum viable set of elements; especially when they are described without going into detail.