E-Channel

e-Channel, also known as The Automated Passenger Clearance System, is an expedited border control system introduced by the Hong Kong Immigration Department in 2004, designed to speed up border immigration processes for residents of Hong Kong, Macau and frequent visitors to Hong Kong entering and exiting the territory whether it be by land, air or sea via the use of self-service kiosks employed at various border control points.
Basic requirements.
The user upon entrance to the e-Channel inserts their Hong Kong Identity Card into the card reader or places their registered travel document or Macau Identity Card onto the document reader. The gate opens and the user steps in, scans their fingerprint and allows entry to Hong Kong.
Locations.
First made available on 16 December 2004 in Lo Wu Control Point, over the past several years the locations have expanded to include:
By allowing registered users to utilise the self-service kiosks to pass through Hong Kong immigration, processing time averages around 12 seconds making "E-channels" far more efficient than traditional immigration counters.
Macau.
Since its first inception where only Right to Abode Hong Kong Permanent Identity Card holders were permitted to use the self-service kiosks, the program expanded on 12 September 2006; allowing not only those of Right to Land or those with unconditional stay in Hong Kong but also to those residents and non-residents with "notification labels" to use the "E-Channels".
The program was expanded further again on 10 December 2009 to allow holders of Macau Resident Identity Card to register for and use of the Hong Kong "E-channels" to enter and exit the territory.
Vice versa, Macau have reciprocated and have their set of "E-Channels" and Hong Kong ID Card holders can register for those as well. Border cities to Macau and Hong Kong on the Mainland China's side - Zhuhai and Shenzhen (respectively) have their set of E-channels for use of the Home Return Permit cards.
Example: 
A Hong Kong resident arrives at Lo Wu and passes through Hong Kong's "E-Channel" with his Hong Kong Identity Card allowing him to exit Hong Kong, upon approaching a border check point at Shenzhen, he uses his Home Return Permit on China's "E-Channel" to enter Mainland China. Thereby cutting down time compared with using traditional immigration counters.
Or
A Hong Kong resident departs from the Hong Kong-Macau Ferry Terminal clearing through Hong Kong immigration via "E-channel", upon arrival of Macau's Outer Harbour Ferry Terminal, he can use his Hong Kong Identity Card to clear through Macau's set of "E-Channels", instead of queuing up at immigration counters.
Frequent Visitor Automated Passenger Clearance.
Not only has Macau Resident Card holders been permitted to register for this program but frequent visitors to Hong Kong can register for this as well. The "Frequent Visitor Automated Passenger Clearance" would require a valid travel document with a multiple visit visa (if applicable), plus on one of the following documents:
e-Channel Service for foreign nationals.
The Frequent Visitor program was further expanded to nationals of the following countries. Such arrangements are reciprocal and eligible HKSAR passport holders may also enrol for the respective automated border clearance schemes under these countries:
One Stop Customs and Immigration Clearance.
A special vehicular "E-Channel" has been erected for Shenzhen Bay known as "One Stop Customs and Immigration Clearance" for goods vehicle passing through the Shenzhen Bay Control Point, indicating how versatile this system is, and an asset for the Hong Kong Immigration Department.