Eliza is a visual novel. The player takes the role of Evelyn, a young woman who was initially successful in the high-tech industry of Seattle before burning out, and was mostly disconnected from life for about three years. In the present, she serves as the human proxy for Eliza, a virtual counselling program named after the real-life ELIZA, one of the earliest attempts at artificial intelligence in the 1960s. Evelyn reads off what the program produces to tell the clients. Evelyn is required to stay on script produced by Eliza, but this creates difficult choices for her in how she talks to the clients and to others including old friends. Later, Evelyn is given the opportunity to read "off-script", creating scenarios that may affect herself directly. The player has the ability to choose how Evelyn behaves in some cases, affecting how the story progresses. After finishing the game, the player can go back to previous chapters and make different decisions to see how this affects the various endings.
Source: Wikipedia, "[en.wikipedia.org/wiki/Eliza_%28video_game%29 Eliza (video game)]", available under the CC-BY-SA License.