It can talk back and forth with a server all it wants, without the user ever knowing about what's really going on.

它可以根据需要自行与服务器进行交互，用户甚至可以完全不知道幕后发生的一切。

youdao

Please turn off your cell phones in the venue. Please do not frequently stand up for photo taking, or walk back and forth down the aisle, or talk in a loud voice.

在会场内采访期间，请关闭手机，请不要经常起身照相或来回走动，请不要大声喧哗。

youdao

She and the aide knew each other well, and the talk swirled back and forth for a few minutes.

NEWYORKER: The Reptile Garden

She'd come out of surgery the day before, screaming all night, but we were used to that in one another and could sleep through noises of pain and sadness, or talk through them, about movies and boyfriends and sex and God, back and forth across the beds.

NPR: Excerpt: 'Warm Springs'