大侠帮忙说一上语句的意思

大侠帮忙说一下语句的意思
 String.Format(@"
                            <ROOT>
                                <PARA>
                                    <CLASSINFO>LC1111</CLASSINFO>
                                    <PATYPE>2</PATYPE>
                                </PARA>
                                <DATA>
                                    <R>
                                        <CONDITION>{0}</CONDITION>
                                        <OPTYPE>1001</OPTYPE>
                                    </R>
                                </DATA>
                            </ROOT>", sql);
------解决方案--------------------
字符串格式化，将{0},替换为 sql