In the past a service pack would be a large roll up of updates seen over a year's time while 10 is seeing an entirely newer build instead. For the TH2 that simply mean more updates included for each newer 10585.xxx number. the 318 can also reflect being a mobile not desktop variation of the same build that might see 10586.168.
Details for image : H:\sources\install.wim
Index : 1
Name : Windows 10 Pro
Description : Windows 10 Pro
Size : 14,516,205,352 bytes
WIM Bootable : No
Architecture : x64
Hal : acpiapic
Version : 10.0.10586
ServicePack Build : 0
ServicePack Level : 0
Edition : Professional
Installation : Client
ProductType : WinNT
ProductSuite : Terminal Server
System Root : WINDOWS
Directories : 20596
Files : 105228
Created : 27/04/2016 - 07:27:20
Modified : 27/04/2016 - 07:27:57
The operation completed successfully.
That ISO file was current on April 27, so you will get the Windows Updates from April 27 to now. The build in the ISO file is probably 10586.117.
That will likely only be about 2 or 3 at the most in only a little over a month's time. If you have things set to auto you will likely not even notice when those go on unless one requires a full restart and gets scheduled for it.
May I suggest a more universal and secure link to the Tech Bench program page ?
Note https instead of http, and en-us removed, so that it displays according to each visitor's language parameters.