Sthavar (often written as sthavara) means immovable beings. In Jain philosophy, all life is classified into two broad groups: movable (charvar) and immovable (sthavar).

• Sthavar beings are those that do not move of their own accord—primarily plants, trees, shrubs, and other fixed-life organisms. They are sentient (jiva) and subject to karma, just like other living beings, but they do not have the power of locomotion.
• Movable beings (charvar) include animals, humans, insects, and other beings capable of moving.

There isn’t a major doctrinal difference about this term between Digambara and Śvetāmbara traditions in the basic definition; both acknowledge the category of immovable jivas (sthavar) alongside movable jivas. If you’d like, I can give a brief note on how each tradition views plant life and senses.