When Plot is clicked in the data input dialogue, pH will first carry out the calculations required using the data from that window. Some checking of the input data for sanity is done, but it is up to the user to enter sensible values.
Assuming the calculations complete successfully, a window opens showing the pH curve for the simulated titration in graphical form. An example is shown below.

The graph menu
There are two main options in the graph menu.
Indicators
This leads to a submenu giving a listing of common acid-base titration indicators.

Clicking on one of these will place on the titration curve graph a shaded rectangle showing the region over which the indicator will change from one colour to the other. A heading will also be placed on the graph giving the indicator name and the pH range over which it will change colour.
There is a final choice, 'no indicator', which will remove the indicator representation from the graph. See the graph above.
The image below shows the pH graph with an indicator included.

Save as
This leads to a submenu with two options.

- Save as MultiPlot will save the pH curve data in MultiPlot format, which can be subsequently loaded into MultiPlot.
- Save as CSV will save the pH curve data as a text file in CSV format.