<?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>2101100 - Disclosure - Background</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>D2013Q2YTD</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000047129</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>hzc_BackgroundDisclosureAbstract</ElementName><ElementPrefix>hzc_</ElementPrefix><IsBaseElement>false</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>Background Disclosure [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><PreferredLabelRole>terseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="D2013Q2YTD" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="font-family:Times New Roman;font-size:10pt;"&gt;&lt;div style="line-height:120%;padding-bottom:10px;padding-top:10px;text-align:justify;font-size:10pt;"&gt;&lt;font style="font-family:Arial;font-size:10pt;font-weight:bold;"&gt;Background&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;padding-bottom:8px;text-align:justify;font-size:10pt;"&gt;&lt;font style="font-family:Arial;font-size:10pt;"&gt;The Hertz Corporation together with its subsidiaries, including Dollar Thrifty Automotive Group, Inc., or "Dollar Thrifty,"  are referred to herein as &amp;#8216;&amp;#8216;we,&amp;#8217;&amp;#8217; &amp;#8216;&amp;#8216;our&amp;#8217;&amp;#8217; and &amp;#8216;&amp;#8216;us.&amp;#8217;&amp;#8217; The Hertz Corporation is referred to herein as &amp;#8216;&amp;#8216;Hertz,&amp;#8217;&amp;#8217; &lt;/font&gt;&lt;font style="font-family:Arial;font-size:10pt;color:#000000;text-decoration:none;"&gt;100%&lt;/font&gt;&lt;font style="font-family:Arial;font-size:10pt;"&gt; of Hertz outstanding capital stock is owned by Hertz Investors,&amp;#160;Inc., and &lt;/font&gt;&lt;font style="font-family:Arial;font-size:10pt;color:#000000;text-decoration:none;"&gt;100%&lt;/font&gt;&lt;font style="font-family:Arial;font-size:10pt;"&gt; of Hertz Investors,&amp;#160;Inc.'s capital stock is owned by Hertz Holdings.&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;padding-bottom:8px;text-align:justify;font-size:10pt;"&gt;&lt;font style="font-family:Arial;font-size:10pt;"&gt;We operate our car rental business through the Hertz, Dollar and Thrifty brands from corporate, licensee and franchisee locations in North America, Europe, Latin America, Asia, Australia, Africa, the Middle East and New Zealand and our equipment rental business our equipment rental business segment, we rent equipment through in the United States, Canada, France, Spain, China and Saudi Arabia, as well as through our international licensees.  We and our predecessors have been in the car rental business since 1918 and in the equipment rental business since 1965.  We also own Donlen Corporation, or "Donlen," based in Northbrook, Illinois, which is a leader in providing fleet leasing and management services. &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;padding-bottom:8px;text-align:justify;font-size:10pt;"&gt;&lt;font style="font-family:Arial;font-size:10pt;"&gt;On November 19, 2012, Hertz completed the acquisition of Dollar Thrifty, a car rental business. On December 12, 2012, Hertz completed the sale of Simply Wheelz LLC, a wholly owned subsidiary of Hertz that operated our Advantage Rent A Car business. See Note 5&amp;#8212;Business Combinations and Divestitures.&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-align:justify;font-size:10pt;"&gt;&lt;font style="font-family:Arial;font-size:10pt;"&gt;In May 2013, we announced plans to relocate our worldwide headquarters to Estero, Florida from Park Ridge, New Jersey over a two-year period.&lt;/font&gt;&lt;/div&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



Reference 2: http://www.xbrl.org/2003/role/presentationRef

 -Publisher AICPA

 -Name Statement of Position (SOP)

 -Number 94-6

 -Paragraph 10

 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Background</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>Background</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://www.hertz.com/role/Background</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
