Selection styles determine the way you select components in your scene. There are two selection styles in Maya: Marquee and Drag. You can set the selection style in the Tool Settings or the Modeling Toolkit window.
Marquee select
Marquee select draws a rectangular box over the components you want to select. You can interactively adjust marquee selections by dragging a marquee box, and then 
-dragging it to a new position.
-dragging it to a new position. Note: 
You can quickly toggle between the two selection styles using Tab. Holding Tab after making a marquee selection temporarily activates Tab Drag select, letting you quickly add and remove components from your existing marquee selection. See Resize a marquee selection with drag select.
You can quickly toggle between the two selection styles using Tab. Holding Tab after making a marquee selection temporarily activates Tab Drag select, letting you quickly add and remove components from your existing marquee selection. See Resize a marquee selection with drag select. Drag select
Drag select is like Paint Selection without a brush size. This selection style lets you drag the cursor over components you want to select.
Lazy selection
Lazy selection lets you select vertices when your cursor isn't touching them, making selections fast and easy. By default, Maya's preselection highlight and Drag select use lazy selection. See Select multiple components with drag select.