Accessing an SMB shared folder from macOS makes it possible to work with files stored on a Windows PC, another Mac, or a NAS without copying the data locally first. That is useful for team documents, media libraries, and administrative file shares that need to stay in one central location.
Finder connects to file shares through the Go → Connect to Server dialog, where the remote host is entered as an SMB address such as smb://fileserver.example.net. Finder can connect to the server first and show the available shares, or it can open one share directly when the address already includes the share name.
Reliable access depends on the remote host actually offering SMB, the correct hostname or IP address, and an account that is allowed to open the share. When a server publishes multiple shares, Finder may ask which one to mount after authentication; when the address already includes the share name, that chooser is skipped and Finder opens the share directly.

Press Command+K in Finder to open the same dialog without using the menu bar.
smb://fileserver.example.net smb://192.0.2.10
If the exact share name is already known, use a full path such as smb://fileserver.example.net/projects to open that share directly instead of choosing it later from a list.
Finder can pause briefly while it contacts the server and checks which shares are available.
Choose Guest only when the remote share is explicitly configured for guest access. Otherwise use Registered User and enter an account that has permission to the share.
This selection step is skipped when the Server Address already includes the share name.

Mounted network shares appear in the Finder sidebar under Locations, which makes them easier to reopen or eject later.
Eject the share before sleeping the Mac, disconnecting from the network, or shutting down the remote host to reduce the risk of interrupted file copies or partially written files.