Meaning: Under Section 28 to 44 of the Income Tax Act 1961, Profit and Gains of Business or Profession form part of Total Income of an assessee. This head is the most important source of tax collection for the Government. The computation of income under this head is a very complex and difficult method but before going into calculation of income under this head, it is necessary to understood the meaning of terms used in this head. Business: “Business” simply means any economic activity carried on for earning profits. Sec. 2(3) has defined the term as “ any trade, commerce, manufacturing activity or any adventure or concern in the nature of trade, commerce and manufacture”. In this connection it is not necessary that there should be a series of transactions in a business and also it should be carried on permanently. Neither repetition nor continuity of similar transactions is necessary. Profession: “Profession” may be defined as a vacation, or a job requiring some thought, skill and special knowledge like that of C.A., Lawyer, Doctor, Engineer, Architect etc. So profession refers to those activities where the livelihood is earned by the persons through their intellectual or manual skill.