A trademark is a sign used by companies, individuals or companies to distinguish their goods or services from that of others or competitors. In other words, a trademark is used when one wants to make sure that their product or service or name is not used by any other person or entity for their benefit. IT also helps maintain the exclusivity of their product and portrays the authenticity, quality, etc. of the product or service that they are providing.
A trademark can be used for various purposes, so keeping that in mind different goods and services have been classified by the International (Nice) Classification of Goods and Services into 45 Trademark Classes where in 1 to 34 cover goods, and 35 to 45 covers services. A trademark application generally contains details such as, full and legal name of the applicant (it can either be an individual or entity), business address, type of entity and its details, description of the mark, basis for applying, etc. This form is a general template and can be modified as per the requirement which may change from state to state depending on the laws and other factors.