instruction:
In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.
question:
Hypothyroidism , also called underactive thyroid or low thyroid , is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone .
answer:
If a person has hypothyroidism , their thyroid gland does not make enough hormones .

question:
Client server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service , called servers , and service requesters , called clients .
answer:
A client-server application is a distributed system made up of both client and server software .

question:
In computing , a digital object identifier ( DOI ) is a persistent identifier or handle used to identify objects uniquely , standardized by the International Organization for Standardization ( ISO ) .
answer:
A Digital Object Identifier ( or DOI ) is a permanent way to identify an online document .