The C Language: 1.9 Confusing function copy();

The C Language: 1.9 Character Arrays

/*I copied this word for word with the intentions of interpreting it later but i can't figure out what the function copy is doing!*/
#include <stdio.h>
#define MAXLINE 1000 /*Maximum Input Line Length*/
int getline(char s[],int lim);
void copy(char to[],char from[]);

int main() {
  int len;               /*Current line length*/
  int max;               /*maximum length seen so far*/
  char line[MAXLINE];    /*current input line*/
  char longest[MAXLINE]; /*longest line saved here*/
  
  max = 0;
  while((len = getline(line,MAXLINE)) > 0)
    if(len > max) {
      max = len;
      copy(longest,line);
    }
  if (max > 0) /*there was a line*/
    printf("\nThe longest string was:\n%s",longest);
  return 0;
}

int getline(char s[],int limit) {
  int c,i;
  
  for (i = 0; i < limit - 1 && (c = getchar()) != EOF && c != '\n'; ++i)
    s[i] = c;
  if (c == '\n') {
    s[i] = c;
    ++i;
  }
  s[i] = '\0';
  return i;
}

void copy(char to[],char from[]) {
  int i = 0;

  while((to[i] = from [i]) != '\0')
    ++i;
}