Bank statements. One sort of financial record is a bank statement. Your bank will regularly send a statement containing information showing income (credits) and outgoings (debits) on your bank account.
They're synonyms. Gain is the most general. Attain usually means to reach a goal or milestone (he attained the rank of captain). Obtain usually implies careful planning or some effort to get to the thing or goal. But they have probably something like 80% overlap in meaning.
What is the difference between revenue, income, and gain? Revenue is the amount earned from a company's main activities such as selling merchandise or providing services. A gain results from a peripheral activity, such as selling the old delivery truck. A gain is the amount received that is in excess of the asset's carrying amount .