Computers, smartphones, and other machines are the perfect servants. They always do what they are "told". We usually "tell" them to do things by using a mouse or keyboard. But what if we could just talk to them normally and tell them what to do?
This type of technology, known as voice control or voice recognition(识别), has been shown in films and TV shows since the 1960s. The TV show Star 'Trek showed some spaceships which could reply to human voice commands (命令). The film 2001: A Space Odyssey showed a computer that human astronauts could talk to. It was mainly used to play chess and repair the astronauts' spaceship.
On the other hand, real-world voice recognition is used for more everyday tasks. For example, Apple and Amazon made two pieces of voice recognition software(软件). They can be asked to do many things, such as setting alarms and playing music and so on.
One of the nice things about voice recognition is that it can be used when we're on the go. When you're driving a car or walking down the street, it's not convenient or even dangerous to pick up your smartphone and type away on the keyboard. Voice recognition allows you to focus on whatever you're doing at the moment while still doing other tasks.
Speech recognition software is also helpful to deaf people. It can be used to "listen" to spoken words and turn them into text that deaf people can read. Some speech recognition software can even hear words spoken in one language and then translate them into another language.