Valley Floor Tour is a two-hour tour of Yosemite Valley that operates all year. From approximately April through October, this is an open-air tram tour (weather permitting). From around October through March, this is a bus tour.
Glacier Point Tour is a four-hour round-trip tour to Glacier Point and back. (One-way tickets are available.) This tour operates when the Glacier Point Road is open (typically, late May until sometime in November, conditions permitting).
Grand Tour is a full-day tour (~ 8 hours) that visits Yosemite Valley, Glacier Point and the Mariposa Grove of Giant Sequoias. This tour operates during the late spring through summer (May – September, conditions permitting).
Tuolumne Meadows Tour is an all-day tour to Tuolumne Meadows and back. (One-way tickets are available.) This tour operates from July through early September, conditions permitting.