Default adb back up

adb backup -apk -all -f backup.ab

where does that command land the backup on one computer?
"Their stupidity does not amaze me, its when they're smart that amazes me." - Zappa


Device: HTC One (M7), T-Mobile (US) S-Off
CID: T-MOB010 (PN0713000)
ROM: ViperOne 5.8
HBOOT 1.55
Build: 4.19.401.11
Kernel: 3.4.10
Recovery: TWRP 2.6.3.3

Previous Infestations HTC Sensation
ViperS 1.6.3
ELEGANCIA 4.1 v3.5
ARHD 6.8
Bricked 3 v1.4 lagfree
Faux
OpenSense (fave, wish dev cont'd)
CM9
CM10-20121027