While dividing the container into columns and rows, you can drag and drop the components into the container, and consequently assign them to a logical cell. The component can then use the cell area or extend over several cells (row/column span). In the former case, the component can be further adjusted within the cell. In the latter case, this is not possible.
Enlarge a cell
Using the mouse, you can change the cell range and its expansion over several rows, respectively columns. Position the mouse over the blue rectangles (the cursor changes) and hold the left mouse button down. Move the mouse to indicate the cell range.§
Moving a cell
To assign the component to another cell, grab the blue frame and then pull the component to the desired cell.