What a report program is
A report is the most classic ABAP deliverable: a program that reads business data, processes it, and presents the result to a user. Most reports follow the same rhythm — selection screen, data selection, processing, output.
The selection screen
Reports usually start by asking the user what they want to see. PARAMETERS and SELECT-OPTIONS let the user filter by company code, date range or material number, so one program can answer many different questions.
Reading and processing data
Open SQL reads data from the database into internal tables — think of them as in-memory spreadsheets your code can loop over. The art of ABAP is choosing the right table type and processing the data efficiently.
Modern ABAP also offers inline declarations and expressions that make this code shorter and clearer than the classic style, while the underlying ideas stay the same.
Showing the result
The classic way to display results is the ALV grid, which gives users sorting, filtering and totals almost for free. Learning to present data well is what turns a working program into a useful one.
Learning by doing
The fastest way to learn ABAP is to build small reports against real-looking business data, then debug them line by line. Understanding what the debugger shows you teaches more than any amount of reading.