Need explanation of the given question For Programming language: PHP

Question 2:

Identifier name, scope, lifetime, etc: Is the language case-sensitive? which words are keywords/reserved words in this language? Can those words be used as identifier names? Do the variables start with any special character? If so, what are their meanings? Discuss when each category of variable-name binds with memory cell and with a type (e.g. in C++, static local variable binds with memory during load-time and each variables type is bound during compile time). Mention whether variables types are determined implicitly/explicitly and/or whether type can change dynamically. Categorize variables in this language based on lifetime as well as based on scopes. Justify your answers and explain your answers using code-snippets. . If the language is a declarative one and as such has no concept of variables in imperative language, then please discuss its difference with imperative languages variables and other relevant issues (e.g. its scope, lifetime, etc.)