Could anyone tell me what happens in this batch file?

Can anyone explain me what happens here:
@pushd ..
call .\DownloadUpdates.cmd w60 glb /verify /skypdynamic
@popd
@pushd ..
call .\CreateISOImage.cmd w60 glb
@popd
@pushd ..
call .\CopyToTarget.cmd w60 glb "C:\Users\xx\Desktop\USB-map"
@popd
I understand it downloads the Windows Vista 32 bit updates en verifies the updates and skips the dynamic updates en makes an iso.
But what does the `pushd`, `popd` do? and how does it find the \DownloadUpdates.cmd? Does it makes this DownloadUpdates.cmd with the pushd command?
@pushd ..
call .\DownloadUpdates.cmd w60 glb /verify /skypdynamic
@popd
@pushd ..
call .\CreateISOImage.cmd w60 glb
@popd
@pushd ..
call .\CopyToTarget.cmd w60 glb "C:\Users\xx\Desktop\USB-map"
@popd
I understand it downloads the Windows Vista 32 bit updates en verifies the updates and skips the dynamic updates en makes an iso.
But what does the `pushd`, `popd` do? and how does it find the \DownloadUpdates.cmd? Does it makes this DownloadUpdates.cmd with the pushd command?