Wireshark dissects protocols and gives debugging traces. Zeek (FKA "Bro") is an intrusion detection system that analyzes debugging traces (which it generates itself, not through Wireshark dissectors) to generate usefully semantic data, ranging from "which hosts are fetching this URL" to "where are there signs of this vulnerability being exploited".

Both Wireshark and Zeek use libpcap, which is the de facto standard for raw packet captures, so yes, the same data you'd be feeding to Wireshark to browse, you can also feed to Zeek to analyze.