Residents are the users of Second Life, and their appearance is their avatar (often abbreviated to av, avi or avie). The basic avatar is human in appearance, but avatars may be of either sex, have a wide range of physical attributes, and may be clothed or otherwise customized to produce a wide variety of humanoid and other forms. Avatars may be completely creative or can be made to resemble the person whom they represent. A single person may have multiple accounts, and thus appear to be multiple Residents (a person's multiple accounts are referred to as alts). However, the use of additional accounts requires the Resident to register them and pay a small fee, though after May 2006, there is no verification process preventing users from creating multiple "first" accounts using false information, a common practice.Also, a single Resident's appearance in Second Life can vary dramatically at will, as avatars are easily modified.
Communication in SL:
Within Second Life, there are two main methods of text-based communication: local chat, and global "instant messaging" (known as IM). Chatting is used for public localized conversations between two or more avatars, and can be "heard" within 20 m. Avatars can also 'shout' ('audible' within 96 m) and 'whisper' ('audible' within 10 m). IM is used for private conversations, either between two avatars, or between the members of a group. Unlike chatting, IM communication does not depend on the participants being within a certain distance of each other. As of version 184.108.40.206, voice chat is also avalible on the main grid using technology licenced by Vivox, a provider of similar services to other MMO worlds.
Moving In SL:
The most basic method of moving around is by foot (also running and jumping). To travel more rapidly, avatars can also fly up to about 170 m above the terrain (meaning 270 m if ground level is 100 m, 180 m if ground level is set to 10 m) without requiring any special equipment, and with scripted attachments there is currently no limit to how high an avatar can fly (although once past several thousand meters, the rendering of the avatar mesh starts to be affected).
Avatars can also ride in vehicles; many vehicles are available—there is a basic go-kart contained in the object library and there are many Resident-made vehicles available freely and for purchase including helicopters, submarines and hot-air balloons. Airborne vehicles can fly up to about 4000 m high (the maximum altitude allowed for any object).
For instantaneous travel, avatars can teleport (commonly abbreviated to "TP") directly to a specific location. An avatar can create a personal landmark (often called an LM) at their current location, and then teleport back to that location at any time, or give a copy of the landmark to another avatar. There's also a map window that allows direct teleportation anywhere.
There are some external websites that allow Residents to locate each other from outside of the virtual world, and SLurl.com allows external links through the Second Life World Map to locations in-world.