Tectonic Plate?

Earth's lithosphere is broken into tectonic plates that move relative to one another. Tectonic processes are driven by forces within Earth (Keller 33).  Plate tectonics are often the cause of natural hazards such as volcanoes and earthquakes. All major plates include an ocean basin and a part of the continent. Plates can be small or large There are three types of plate boundaries: divergent, convergent and transform.

1. Divergent: Divergent boundaries occur when neighboring parts of plates are moving away from each other and new lithosphere is being produced (Keller 36). 
   
2. Convergent: Convergent boundaries occur when plates move towards each other (Keller 36). 
   
3. Transform: Transform boundaries occur when the edges of two plates slide past each other like the San Andreas fault in California (Keller 38). 
   

Everything living on Earth is affected by plate tectonics. The types of and properties of the rocks which we depend for land, our mineral and rock resources, and soils in which our food is grown  is determined by the tectonic processes occurring in the plate boundaries (Keller 48).

Costa Rica is in the Caribbean Tectonic Plate with the Cocos Plate to the West. The Cocos plate moves Northeast relative to the Caribbean plate. Frequent earthquakes and volcanic activity happen in Costa Rica due to the competitive movement between the two plates.

Source: 

Keller, Edward A., et al. Natural Hazards, Earth's Processes as Hazards, Disasters, and Catastrophes. Fourth Edition. 20