understanding the usage of e inside carasoul.js

understanding the usage of e inside carasoul.js

hey guys i was just going through the code of carousel.js and i am a little bit confused , now we it comes to attaching events i ofte see code as follows ::  

  
    
   
  1. $('a').click(fuction(e){
    2. 
   
  2.  if(e.target.targetNode == $(this)[0])
    3. 
   
  3.  //do something
    4. 
   
  4. });
    5. 
  

  

   I am still a bit confused , who is passing the e ? WHO really is passing that e inside the function ? also in the plugin code i see things like the below : 
  

  

   

  

  

   

  

  

   
    
    
     
  1. Carousel.prototype.keydown = function (e) {
    2. 
     
  2.  if (/input|textarea/i.test(e.target.tagName)) return
    3. 
     
  3.  switch (e.which) {
    4. 
     
  4.  case 37: this.prev(); break
    5. 
     
  5.  case 39: this.next(); break
    6. 
     
  6.  default: return
    7. 
     
  7.  }
    8. 
    

    

     an event handler is attached like so : 
    

    

     

    

    

     
      
    
       
  1.  this.options.keyboard && this.$element.on('keydown.bs.carousel', $.proxy(this.keydown, this))
    2. 
      

      

       another example is here : 
      

      

       

      

      

       
        
    
         
  1. Carousel.prototype.pause = function (e) {
    2. 
         
  2.  e || (this.paused = true)
    3. 
         

    4. 
         
  4.  if (this.$element.find('.next, .prev').length && $.support.transition) {
    5. 
         
  5.  this.$element.trigger($.support.transition.end)
    6. 
         
  6.  }
    7. 
         
  7.  this.interval = clearInterval(this.interval)
    8. 
         
  8.  return this
    9. 
         
  9.  }
    10. 
        

        

         

        

        

         
Who is passing e inside these functions , from where is it coming from ? i have absolutly no clue , i have been using JS for a while now , but this still baffles me . can somebody really clear this doubt for me once and for all ?

         
P.S. I have seen this answer on SO , but it does't answer the questions i have asked . I understand that e is in a way a object with differentv properties that we can access.