We usually not only send documents to others, but also send some folders.
我们平时要发送文件给别人，也要发一些文件夹，
These files and folders are not very large, but the number of them is many, so it is very troublesome to send one by one, and more troublesome for others to receive in the same way. Even the contents is mistaken sometimes so that people will not know what the senders are talking about when they receive it.
这些文件和文件夹又没有多大，个数又多，一个一个地发很麻烦，别人接收起来更麻烦。甚至把目录都要搞错，别人接收起来，也不知道讲的是什么东西。
In this case, we will pack and send all the files and folders, so that others can accept them more easily, and we will save time in sending them.
碰到这种情况，我们就要把所有的文件和文件夹打包发送，这样别人接受起来也比较方便，我们也省事。
Bundle them together into an RAR document and pack them together into a RAR file.
把它们打包在一起变成一个RAR文件。
But many mailboxes often have a rule on the size of documents, some are 20 megabytes, some are 50 megabytes, depending on different platforms,
但是很多邮箱往往对文件的大小有个规定，有的是20兆，有的是50兆，
so sometimes they have to be packed twice.
所以有时候要分两次打包。
Bundle them together into two RAR documents,That's all right.
把它们打包在一起变成两个RAR文件。这样就没问题了。
When size requirements are obvious, I.e. the size of the file has obvious requirements, we will pack according to the required file size.
文件的大小有明显的要求，我们就按要求的文件大小去打包。
To bundle several files together is a big benefit. Packing several folders together is a great benefit.
把几个文件夹打包在一起好处很大，
Let each other not download one after the other. We also don't upload one after the other. Not to download or up load one after the other is very good for receiving and sending documents.
让对方不要去一个一个的下载，我们也不要一个一个的去上传，对接收和发送都是很有好处的。
