1. Application Scenarios 1.1 Mail RFC821 requires that email content be ASCII. When a message contains other non-ASCII characters or binary data, Content-Transfer-Encoding is needed, and Base64 is one such method. 1.2 URL Some applications need to put binary data into a URL, but URLs only allow a specific set

1. Font-family The fonts you can use on a web page are limited to the handful of fonts already installed on the PC the browser is running on. Windows operating system, Chinese fonts: SimHei (Hei) SimSun (Song) NSimSun (New Song) FangSong (FangSong) KaiTi (Kai) FangSongGB2312 (FangSong GB2312) KaiTiGB2312 (Kai GB2312)

1. What Docker Is Docker was born in early 2013 as a side project inside dotCloud (the former name of Docker Inc.). Its source code is hosted on GitHub, it is written in Go, and it follows the Apache 2.0 open-source license. The goal of the Docker project is to provide a lightweight operating system virtualization solution.

1. Basic Concepts Symmetric encryption: Symmetric encryption is an encryption method that uses a single-key cryptosystem, in which the same key is used both to encrypt and to decrypt the information. Because it is fast, it is often used to encrypt the transmission of large amounts of data. DES (Data