simple

Having few parts or features; not complicated or elaborate.

Easy to understand, do, or carry out: synonym: easy.

Having or composed of only one thing, element, or part.

Being without additions or modifications; mere.

Having no divisions or branches; not compound.

Being without figuration or elaboration.

Having little or no ornamentation; not embellished or adorned: synonym: plain.

Not characterized by luxury or elaborate commitments.