Method Group

What is a method group and how can I use it?

FRef.cs:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class FRef : MonoBehaviour {
    string player_n;
    public List<Prop> p = new List<Prop>();
    int idx;

    void Start()
    {
        idx = p.FindIndex(IsAlive);
        Debug.Log(p[idx].name);
    }

    bool IsAlive(Prop stats)
    {
        return stats.health == 100;
    }
}

And classes.cs:

using UnityEngine;
using System.Collections;
using System;

public class Classes {

}
[Serializable]
public class Prop
{
    public string name;
    public int health;
}

Is it something like this? If so, where can I find documentation about it?

the first accepted answer here describes it:

http://stackoverflow.com/questions/886822/what-is-a-method-group-in-c