can i connect to my icloud from multiple computers?

You can open a new tab ( use command and T keys ) on multiple Macs that are connected on the same network or on a different network , essentially only Apple ID and password with credentials for secondary authentication account ( in which three answers for respective security questions , date of birth , rescue mail address and its password is added ) or if account is set with two factor authentication at www.icloud.com

Its not necessary all Macs are always connected to the same network , they can be on different network , only you need is correct credentials to sign in iCloud.com

Note : on iPhone you can't directly open www.icloud.com