An alternate timeline, as its name suggests, is a timeline different to another, usually caused by temporal interventions due to time travelling mission(s). For example, in The New John Connor Chronicles timeline, there are three different alternate timelines caused by various time travelling missions: Skynet's World, Jade's World (caused by Destruction of Cyberdyne Building, and John's World (caused by a team of Specialists travelling from 2036 to 2001).
Another example is Genisys timeline, due to the attempted assassination of Sarah Connor in 1973, Sarah Connor has already well trained to fight against the Machines in 1984, whereas in most of the timelines, Sarah Connor is just an ordinary person before her encounter with the T-800 and Kyle Reese in 1984.
- The term "alternate timeline" is first used on-screen by Pops in the 2015 film Terminator Genisys.
- As shown in the image right to these texts, Rise of the Machines timeline, The Sarah Connor Chronicles timeline, Dark Fate timeline, and Genisys timeline are different alternate timelines to each others.
- Original timeline
- Alternate original timeline
- Alternate future
- Single timeline - a concept contrast with the alternate timeline
- Parallel universe (fiction) at Wikipedia