What is meant by the term 'breed'? What are the objectives of animal breeding?

(N/A) breed is a group of animals related by descent and similar in most characters like general appearance,features,size,configuration,etc.
Objectives of animal breeding:
$1$. To increase the yield of animals (e.g.,milk,meat,eggs).
$2$. To improve the desirable qualities of the animal produce (e.g.,higher fat content in milk,better quality of wool).
$3$. To produce disease-resistant varieties of animals to reduce losses due to infections.