This is the 928th most frequent Russian word.
открыть
"To open."
Here, 'открыть' means 'to open' in a literal sense, referring to the action of making an object, like a window, open.
Я открыл окно, чтобы проветрить комнату.
I opened the window to ventilate the room.
In this case, 'открыть' is used metaphorically to mean 'to discover' or 'to find out about something new'.
Вчера я открыл для себя новую интересную книгу.
Yesterday, I discovered a new interesting book for myself.
Here, 'открыть' is used to describe the initiation or beginning of an event or activity.