Question 1194362
{{{X^2-4X- 4Y +16=0}}}

preferring all lower case,
{{{x^2-4x- 4y +16=0}}}

{{{x^2-4x=4y-16}}}

{{{x^2-4x+4=4y-16+4}}}

{{{(x-2)^2=4y-12}}}

{{{highlight_green((x-2)^2=4(y-3))}}}
With this, if you compare to  (x-h)^2=4p(y-k), then p=1, or the focus and directrix each is 1 unit from the vertex; 
and
for your example, 
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vertex  (2,3)
parabola is with vertical symmetry axis with vertex as minimum;
focus (2,4)
directrix  y=2
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