You use basically for emphasis when you are stating an opinion, or when you are making an important statement about something. 基本上; 主要地
adverb [方式副词]基本上,大体上;从根本上说,总的说来
You use basically to show that you are describing a situation in a simple, general way, and that you are not concerned with less important details. 简单来说; 大致说来