You can specify fixedRowCount property of displayOptions of the grid to fix one or more top rows. The fixed rows are excluded from the vertical scroll. And, they are also excluded from Sorting and Filtering.
In the grid below, the number of Fixed Rows has been set as 2.
Basically, the cells contained in the fixed row are drawn by the style specified in fixedRowStyles or fixedCellStyles of body rather than the column style.