I have a question about the difference between 'diagram' and 'graph'

I'm preparing IELTS exam and I got a problem with TASK 1 in writing part. I want to explain about a flow chart using 'synonym of flow chart' and the synonym was 'graph'. However, my English tutor said to me those are not synonyms at all. This is why I was getting confused what is the difference between the word 'flow chart' and 'graph'.

My question is this. Does the word 'graph' includes the definition (or meaning) of the word 'flow chart'? Or are they totally different words as my tutor mentioned earlier?

Solution 1:

Flow Charts:

Symbolic representation of process is called Flow charts. So different symbols are used to denote process which contains a little description of the process.

Graphs

A diagram showing the relation between variable quantities, typically of two variables, each measured along one of a pair of axes at right angles.

The main difference between a graph and chart is that unlike a chart, a graph is exactly measured and is plotted on axes.
Also, a chart consists of different symbols while a graph may only consist of lines.

Some synonyms of Flow chart are:

• Process flow charts
• Process map
• Process chart
• Process model
• Process flow diagram
• Flow diagram