Apple - Are apsd, ntpd, mDNSResponder, trustd, netbiosd necessary for macOS functioning?
apsd - Used for FaceTime push notifications
ntpd - Used to synchronize clock
mDNSResponder - Part of the Bonjour protocol, used to scan your network for other Bonjour-enabled devices (printers, computers, etc...)
trustd - Used for validating SSL certificates
netbiosd - Used when interacting with Microsoft shared drives
This is all normal activity. However, if you are worried about security, you can disable the services you don't plan on using.
Edit: You might not want to disable
trustd as they are necessary for basic functionality such as browsing websites.