<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>0009 - Disclosure - Business</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName /><CurrencySymbol /><contextRef><ContextID>From2013-01-01to2013-06-30</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001005817</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2013-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2013-06-30T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="6 Months Ended" /><Label Key="Calendar" Id="1" Label="Jun. 30, 2013" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Organization, Consolidation and Presentation of Financial Statements [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>us-gaap_NatureOfOperations</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="From2013-01-01to2013-06-30" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: left"&gt;&lt;font style="display: inline; font: bold 10pt Times New Roman"&gt;1. Business&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block"&gt;&amp;#160;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;Tompkins Financial Corporation (&amp;#8220;Tompkins&amp;#8221; or the &amp;#8220;Company&amp;#8221;) is headquartered in Ithaca, New York and is registered as a Financial Holding Company with the Federal Reserve Board under the Bank Holding Company Act of 1956, as amended. The Company is a locally oriented, community-based financial services organization that offers a full array of products and services, including commercial and consumer banking, leasing, trust and investment management, financial planning and wealth management, insurance, and brokerage services.&lt;font style="display: inline; font: bold 10pt Times New Roman"&gt;&amp;#160;&lt;/font&gt;At June 30, 2013, the Company&amp;#8217;s subsidiaries included:&amp;#160;&amp;#160;four wholly-owned banking subsidiaries, Tompkins Trust Company (the &amp;#8220;Trust Company&amp;#8221;), The Bank of Castile, Mahopac National Bank, VIST Bank; TFA Wealth Management, Inc., a wholly owned registered investment advisor (&amp;#8220;TFA Wealth Management&amp;#8221;); and a wholly-owned insurance agency subsidiary, Tompkins Insurance Agencies, Inc. (&amp;#8220;Tompkins Insurance&amp;#8221;). TFA Wealth Management and the trust division of the Trust Company provide a full array of investment services under the Tompkins Financial Advisors brand, including investment management, trust and estate, financial and tax planning as well as life, disability and long-term care insurance services.&amp;#160;&amp;#160;VIST Bank, through its VIST Capital Management brand (&amp;#8220;VIST Capital Management&amp;#8221;) provides investment advisory, retirement planning solutions, and brokerage services to our customers in southeastern Pennsylvania.&amp;#160;&amp;#160;The Company&amp;#8217;s principal offices are located at The Commons, Ithaca, New York, 14851, and its telephone number is (607) 273-3210.&amp;#160;&amp;#160;The Company&amp;#8217;s common stock is traded on the NYSE MKT LLC under the Symbol &amp;#8220;TMP.&amp;#8221;&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block"&gt;&amp;#160;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;As a registered financial holding company, the Company is regulated under the Bank Holding Company Act of 1956 (&amp;#8220;BHC Act&amp;#8221;), as amended and is subject to examination and comprehensive regulation by the Federal Reserve Board (&amp;#8220;FRB&amp;#8221;). The Company is also subject to the jurisdiction of the Securities and Exchange Commission (&amp;#8220;SEC&amp;#8221;) and is subject to disclosure and regulatory requirements under the Securities Act of 1933, as amended, and the Securities Act of 1934, as amended.&amp;#160;&amp;#160;The Company is subject to the rules of the NYSE MKT LLC for listed companies.&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block"&gt;&amp;#160;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;The Company&amp;#8217;s banking subsidiaries are subject to examination and comprehensive regulation by various regulatory authorities, including the Federal Deposit Insurance Corporation (&amp;#8220;FDIC&amp;#8221;), the Office of the Comptroller of the Currency (&amp;#8220;OCC&amp;#8221;), the New York State Department of Financial Services (&amp;#8220;NYSDFS&amp;#8221;), and the Pennsylvania Department of Banking and Securities (&amp;#8220;PDBS&amp;#8221;).&amp;#160;&amp;#160;Each of these agencies issues regulations and requires the filing of reports describing the activities and financial condition of the entities under its jurisdiction. Likewise, such agencies conduct examinations on a recurring basis to evaluate the safety and soundness of the institutions, and to test compliance with various regulatory requirements, including: consumer protection, privacy, fair lending, the Community Reinvestment Act, the Bank Secrecy Act, sales of non-deposit investments, electronic data processing, and trust department activities.&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;&amp;#160;&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;The Company&amp;#8217;s wealth management subsidiary is subject to examination and regulation by various regulatory agencies, including the SEC and the Financial Industry Regulatory Authority (&amp;#8220;FINRA&amp;#8221;).&amp;#160;&amp;#160;The trust division of Tompkins Trust Company is subject to examination and comprehensive regulation by the FDIC and NYSDFS.&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;&amp;#160;&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: 10pt Times New Roman"&gt;The Company&amp;#8217;s insurance subsidiary is subject to examination and regulation by the NYSDFS and the Pennsylvania Insurance Department.&lt;/font&gt;&lt;/div&gt;

&lt;div style="text-indent: 0pt; display: block; margin-left: 0pt; margin-right: 0pt; text-align: justify"&gt;&lt;font style="display: inline; font: bold 10pt Times New Roman"&gt;&amp;#160;&lt;/font&gt;&lt;/div&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>The entire disclosure for the nature of an entity's business, the major products or services it sells or provides and its principal markets, including the locations of those markets. If the entity operates in more than one business, the disclosure also indicates the relative importance of its operations in each business and the basis for the determination (for example, assets, revenues, or earnings).</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef

 -Publisher FASB

 -Name Accounting Standards Codification

 -Topic 275

 -SubTopic 10

 -Section 50

 -Paragraph 2

 -URI http://asc.fasb.org/extlink&amp;oid=6927468&amp;loc=d3e6003-108592



</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Business</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>Business</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>true</HasCustomUnits><IsEmbedReport>false</IsEmbedReport><IsMultiCurrency>false</IsMultiCurrency><ReportType>Sheet</ReportType><RoleURI>http://tompkinstrustco.com/role/Business</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
