A software updating apparatus that is connected to a server and a plurality of control apparatuses and performs transmission and reception of data, the software updating apparatus comprising: a first communication unit that receives update control information, which includes update data for each of the plurality of control apparatuses and identification information for identifying an application method for applying the update data to a particular control apparatus, from the server; a second communication unit that transmits the update data to be applied, for each of the plurality of control apparatuses; an update control unit that controls the plurality of control apparatuses via the second communication unit such that the update data is applied based on the identification information, wherein identification information for uniquely identifying the particular control apparatus on an in-car network is included in the update control information, and the update control unit transmits and receives data to and from the particular control apparatus based on the identification information for uniquely identifying the particular control apparatus on the in-car network, wherein the identification information comprises a region of a logical block of a nonvolatile memory that stores software of the particular control apparatus that is set to an application method selected from the following list of application methods: full update, difference update, and compression and decompression update for each of the plurality of control apparatuses, wherein the update control unit gives erasing instruction of a nonvolatile memory of the control apparatus after transmitting the update data to the control apparatus to which the update data is to be applied in a case where the identification information indicates the difference update, and wherein the update control unit transmits the update data to the control apparatus after giving erasing instruction of a nonvolatile memory of the control apparatus to which the update data is to be applied in a case where the identification information indicates the full update, and wherein, the update control unit transmits data obtained by compressing the data after updating to a particular control apparatus and the particular control apparatus decompresses the received compressed data and then writes the decompressed data in its memory, in a case where the identification information indicates the compression and decompression update. a first communication unit that receives update control information, which includes update data for each of the plurality of control apparatuses and identification information for identifying an application method for applying the update data to a particular control apparatus, from the server; a second communication unit that transmits the update data to be applied, for each of the plurality of control apparatuses; an update control unit that controls the plurality of control apparatuses via the second communication unit such that the update data is applied based on the identification information, wherein identification information for uniquely identifying the particular control apparatus on an in-car network is included in the update control information, and the update control unit transmits and receives data to and from the particular control apparatus based on the identification information for uniquely identifying the particular control apparatus on the in-car network, wherein the identification information comprises a region of a logical block of a nonvolatile memory that stores software of the particular control apparatus that is set to an application method selected from the following list of application methods: full update, difference update, and compression and decompression update for each of the plurality of control apparatuses, wherein the update control unit gives erasing instruction of a nonvolatile memory of the control apparatus after transmitting the update data to the control apparatus to which the update data is to be applied in a case where the identification information indicates the difference update, and wherein the update control unit transmits the update data to the control apparatus after giving erasing instruction of a nonvolatile memory of the control apparatus to which the update data is to be applied in a case where the identification information indicates the full update, and wherein, the update control unit transmits data obtained by compressing the data after updating to a particular control apparatus and the particular control apparatus decompresses the received compressed data and then writes the decompressed data in its memory, in a case where the identification information indicates the compression and decompression update.