Will you explain what type of vector this is? Or how this works?

QVector<qulonglong> SysInfoLinuxImpl::cpuRawData()
{
QFile file("/proc/stat");
file.open(QIODevice::ReadOnly);
QByteArray line = file.readLine();
file.close();
qulonglong totalUser = 0, totalUserNice = 0,
totalSystem = 0, totalIdle = 0;
std::sscanf(line.data(), "cpu %llu %llu %llu %llu",
&totalUser, &totalUserNice, &totalSystem,
&totalIdle);
QVector<qulonglong> rawData;
rawData.append(totalUser);
rawData.append(totalUserNice);
rawData.append(totalSystem);
rawData.append(totalIdle);
return rawData;
}