Since you are doing IELTS academic knowing the jargon/technical terminology for graphs charts maps diagrams is a starting point - Axes, X-axis, legend, caption, title, scale, bar-chart, stacked bar chart, pie-chart. If you are talking about numbers, statistics, you will also want to have basic words like trend average median quartile. In my opinion the Academic part I questions are easy-peasy because you talk about facts that are there before you; it only needs you to look carefully and interpret what you see, then organise you thoughts - 15 minutes plus 5 to check and correct.

You are asking about an IELTS writing task, and yet you can't write your question in English? You realize this means that you are not ready to take the IELTS writing test yet, don't you? Are you asking how to use these words? rise/fall (Prices rise and fall.) decrease/increase (The value increased. The priced decreased.) table/graphic/bar/diagram/chart bar (Table is data in columns, like Excel spreadsheet. Graph is a line graph. Bar chart. Diagram is a picture. "Chart bar" => Bar chart.) in similar to (We don't say this. Just "similar to". This graph is similar to that graph. change/exchange (To change is to modify. To exchange is to swap.) between and/from to (between 5 and 10; from 5 to 10)

Econimist 上倒是有很多图表的描述，不过不像雅思要求得那么具体。