The latest hard drives can have more than 500,000 tracks on just one side.

最新的硬盘可以在单面拥有超过50万个道。

To begin, the disk is divided into concentric circles of tracks.

首先，盘被分为一系列同心圆的道。

Thus, we can fit many more tracks and much more data into a given area.

此，我们可以在给定域内放入更多的道数据。

And in the process, we'll look at the tracks, sectors, and magnetic domains of the metal disk.

在这个过程中，我们将查看金属盘上的道、扇性域。

The next part of the sector is the address, which helps the read-write head know which track and sector it's currently positioned over.

扇的下一部分是地址，这有助于读写头知道它当前位于哪一条道哪个扇上。

However, with shingled recording, The tracks are written to partially overlap with previously written tracks, with no guard bands to separate each track.

然而， 使用叠瓦式记录时，道会部分重叠之前写入的道，且没有间隔带来分隔每个道。

Note that the read head is much smaller than the write head, and as a result, one shingled track can be reliably read at a time.

请注意， 读头比写头小得多，此一次只能可靠地读取一个叠瓦式道。

Before shingled magnetic recording, hard drives typically used the technique classic magnetic recording, or CMR, where the tracks of data are 90 nanometers wide and have guard bands on either side of the track.

在叠瓦式记录之前，硬盘通常使用经典记录术，或简称CMR， 其中数据的道宽度为90纳米， 并且每条道两侧都有保护带。

These tracks are then divided into sectors, and in each sector is a preamble or synchronization zone, which tells the read-write head the exact speed of the spinning disk and the length of each bit of data.

这些道被进一步划分为扇，每个扇中都有一个前导码或同步，它告诉读写头盘旋转的确切速度以及每比特数据的长度。