i wonder about privatekeys website

when i check for any addresss , i get the same addresses from different networks bitcoin gold , bitcoin cash ,,,etc
that has the same private key ?

and i wonder how is that possible without knowing the private key from the beginning ??

lets say for puzzle 66
13zb1hQbWVsc2S7ZTZnP2G4undNNpdh5so

Addresses with the same Private Key :

Bitcoin:
bc1qyr2956nky56hqr8fuzepdccejse4mw994lyftn
 0  0  0
Bitcoin Testnet:
miWYJkVaKXJroYbBB8kkrBHEecy5dxNKJP
 0.15650667  0.15650667  15
tb1qyr2956nky56hqr8fuzepdccejse4mw99lel6sq
 0.07957129  0.07957129  15
Bitcoin Cash:
qqsdgkn2wcjn2uqva8sty9hrrx2rxhdc55qw0jqhdh
 0.69
Bitcoin SV:
13zb1hQbWVsc2S7ZTZnP2G4undNNpdh5so
Bitcoin Gold:
GLqWRpjYVMUu6uQrPWSVT2QohoADou8QwG
 0.66  0.66  2
btg1qyr2956nky56hqr8fuzepdccejse4mw99rkzv7m
Litecoin:
LNDYGuiRbA7fHEoidhmgJH8fzqjeseATsU
 0  0  0
ltc1qyr2956nky56hqr8fuzepdccejse4mw993r7dnr
 0  0  0
Dogecoin:
D88gYxMEoumtZSJAC9mwa2EWfm6g3uocon
 25.60472599  25.60472599  9
Dash:
XdgRqx4VUD6CBNi9KT6bsnkhcxx4pyNnFr
 0  0  0
Zcash:
t1LsC22pjUpfCd5ATPzbWA5Aq3HZTZXJWuS
Clams:
xBJDuaF4nDMe4pDRp3R3TSMh1jfcBnESxx
 0  0  0