Why do we need to classify …

Yes

classification is a General term that is used in English that means to sort out the things by a basic criteria however the classification of materials into groups in the language of science has a different meaning the meaning is same but the way we differentiate them is somehow different from the usual differentiation we classify the things in Science according to the properties like physical properties and chemical properties they can also be on the basis of whether a substance can allow light to pass through it or not for example transparent objects are those objects which are low light to pass through them fully but translucent objects allow only a small part of light to pass through them where is opaque objects do not allow this and the chemical properties on which they can be classified is weather they are elements are compounds or mixture another criteria can be according to their chemical nature with the acidic basic or neutral in your higher classes you will study about their reaction with other things whether they are amphoteric or the substances are conductors or insulators on the basis of their conduction of heat and electricity so classification in general means when we sort out things by a common Ness and that commonness can be on the basis that we want

Thank you yogita ?

We classify objects because this make things easier for us. By classifying objects we are able to study about them like their properties, characters,etc.