To jack-in, the crewmember sits in a chair and their limbs are secured as a safety precaution. The operator then inserts the data probe into the crewmember's headjack, plugging the crewmember in. As the crewmember begins to lose consciousness, the consciousness actually gets relayed into the avatar that simultaneously forms within the artificial world or world-space. All of the crewmember's brain signals are then continuously relayed to the Matrix to control the avatar, effectively rendering the physical body unable to move. It should be noted that while the crewmember's brain signals are redirected, the body is still able to send signals to the brain, hence, the need for the body to be secured in place, safeguarding the operative from getting affected by the ship's movements, preventing the head from fatally detaching from the data probe, and protecting the body from getting injured, as any real-world sensation inadvertently gets sent to the brain and up into the avatar who experiences it, seemingly out of nowhere.
Only humans that were grown (i.e. non-born humans like redpills and bluepills) can access the Matrix, which leaves Zion-born (naturally born) humans, who have no headjacks, to serve on hovercraft as operators or other support crew.
Disconnection and extraction
Main article: Extraction
A crewmember's consciousness must likewise be carefully disconnected from the Matrix, initiated from the operator console and using a proper hardline from within the Matrix. Sudden and forced disconnections without a hardline within the Matrix had otherwise always resulted to instant death.
Other simulated reality and construct worlds, like the Construct, allowed the operator to simply disconnect their operatives without using any hardline.
Special Connection of The One
The One was somehow able to jack into the Matrix, or at least got half-way through and got stuck in Mobil Avenue, a construct world between the Matrix and the Real World, without the use of a data probe and without plugging in.
Behind the scenes
While the movies have shown clearly the effect of the moment a user disconnects from the Matrix (the avatar dissolves in green sparkles), they have never shown on screen how an avatar pops up or materializes in the Matrix at the moment a user jacks in. The redpill simply closed his or her eyes when being jacked in and then opened them up in the Construct or in the Matrix.
- There Are No Flowers in the Real World, shows how injuries from the Real World were instantly reflected to the Matrix avatar