Since 2004, Facebook has said it wants to bring the world closer together. To accomplish that goal, the company has relied mostly on the web and smartphone apps.

But software is no longer enough. On Monday, Facebook introduced a pair of video-calling devices — Portal and Portal Plus — to help expand its reach into people’s living rooms.

Portal and Portal Plus, which have a 12-megapixel camera with high-definition video and artificial intelligence software, can be used to do video chats. The A.I.-powered camera follows users as they move, letting them converse without sitting stiffly. The devices also include Amazon’s Alexa, which people can command to play music or check the weather.

Portal, which has a 10-inch screen, will sell for $199, while the other model, with a 15-inch display that can be rotated, will be priced at $349.