c#数据结构 关于排序

Question

public void InsertSort(SeqList<int> sqList)
        {
            for (int i = 1; i < sqList.Last; ++i)
            {
                if (sqList[i] < sqList[i - 1])
                {
                    int tmp = sqList[i];
                    int j=0;
                    for (j = i - 1; j >= 0 && tmp < sqList[j]; --j)
                    {
                        sqList[j + 1] = sqList[j];
                    }
                    sqList[j + 1] = tmp;
                }
            }哪位高手能帮我分析一下第二个for循环语句那啥意思哦，我循环学的不是很好，搞的我很晕。谢谢
for (int i = 1; i < sqList.Last; ++i)
            {
                if (sqList[i] < sqList[i - 1])
                {
                    int tmp = sqList[i];
                    int j=0;
                    for (j = i - 1; j >= 0 && tmp < sqList[j]; --j)
                    {
                        sqList[j + 1] = sqList[j];
                    }
                    sqList[j + 1] = tmp;
                }