What is Milkiyat?

Q:

  1. What is the meaning of having milkiat of something?
  2. A housewife buys something from her husbands money for her personal use or for her children. Who will have milkiat over that thing?
  3. If a man gives something to his close relative or his own children to use, then who will have milkiat over that thing?
  4. What is the difference between a gift to somebody and milkiat over anything?

Mazi

Q: When checking for mazi if I check on my underwear and on top of the private part for mazi or traces of it and find nothing, but when squeezing the private part then only seeing mazi come out after squeezing, is the wudhu broken from before? Or only when  mazi actually flows out after squeezing? No traces could be seen on the private part head or the undergarment. So will wudhu be broken if mazi is there(inside) but didn't flow out?