A question about regular expressions

Question: There is a string: "python php ruby ​​javascript jsonp perhapsphpisoutdated"
For this string, use pure regular expression to get all words with p but not ph

Output array [ 'python', 'javascript', 'jsonp' ]

I have been thinking about this problem for a long time and I have no idea
My solution is

<code>var result = str.match(/\b\w*(?=p)\w*\b/g)
                .filter((value)=>!/.*(?=ph)/.test(value))
var result2 = str.match(  /\b((?!ph|\s).)*((p[^h\s]((?!ph|\s).)*)|p)\b/g  ) 
console.log(result2)</code>

But it does not meet the requirements of pure regularity

A big guy in the group gave this answer

<code>/\b((?!ph|\s).)*((p[^h\s]((?!ph|\s).)*)|p)\b/g </code>

Works perfectly

But I can’t understand it, I hope someone can help me understand it