Creating CDTs

What is the major difference between creating a table from CDT and  creating CDT from a table? On looking from the front end, both look similar. But the XSD file for both of them tell a different story. I have attached both the XSD files here. The one created from table is having columns defined while the other is not having such columns. Will this cause any issues? 

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:tns="urn:com:appian:types:TA" targetNamespace="urn:com:appian:types:TA">
  <xsd:complexType name="TA_tableCDT">
    <xsd:annotation>
      <xsd:appinfo source="appian.jpa">@Table(name="tableCDT")</xsd:appinfo>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:element name="id" nillable="true" type="xsd:int">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Id @GeneratedValue @Column(name="id", nullable=false, unique=true, columnDefinition="INT")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="name" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="name", columnDefinition="VARCHAR(255)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="amount" nillable="true" type="xsd:double">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="amount", columnDefinition="DOUBLE")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="isTrue" nillable="true" type="xsd:boolean">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="isTrue", columnDefinition="BIT")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:tns="urn:com:appian:types:TA" targetNamespace="urn:com:appian:types:TA">
  <xsd:complexType name="TA_TestCDT">
    <xsd:sequence>
      <xsd:element name="id" nillable="true" type="xsd:int">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Id @GeneratedValue</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="name" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(length=255)</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="amount" nillable="true" type="xsd:double" />
      <xsd:element name="isTrue" nillable="true" type="xsd:boolean" />
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>