title: When to correctly use @property/@synthesize, (id)sender and release
body: <p>I have been watching Xcode tutorials on youtube and learning from examples online but could not find a consistency in usage.</p>
  
  <p>I know from  articles on this site that any object created with Alloc/Init, Copy or New must be released.</p>
  
  <p>But:
  - Do all objects have to use @property/@synthesize? Regardless of whether they are IBOutlets or not?
  - Does (id)sender have to be used with all methods (IBAction) and (void) in .h and .m files? </p>
  
  <p>Many Thanks!</p>