Which Ethernet frame field notifies a host that incoming bits represent a frame?

The preamble is a 7-byte field consisting of alternating 1s and 0s (10101010) that synchronizes the receiving host's clock with the incoming bitstream and signals the start of a new frame. It doesn't contain any data but prepares the receiver for the actual frame content. The start of frame delimiter (SFD) is the 8th byte, following the preamble, and signals the actual beginning of the frame. The Type field specifies the protocol encapsulated in the frame's data portion (e.g., IPv4, IPv6). The Data field contains the actual payload being transmitted.