Hi !! Can someone explain this expression.

1) Column One of excel {.pxResults().pxPages(CAOBJ).pyID input} 

This expression is used in Binary File (Excel file) for downloading the data available in Grid.

Here, CAOBJ in () what it indicates? and why it is used  

2) Second Column of excel {MB.pxResults().AccountName input}

In second expression MB is page name of class Code-Pega-List. MB.pxResults is also page of class Index-C-CS-Att-Data-Details This page is defined in activity where we wrote code for call pxGenerateExcelFile.  Can we directly access the Pages that we define in activity into our excel file template?