As a software engineer, I need to deal with networking every now and then – be it configuring a SOHO network, setting up container networking, or troubleshooting connectivity between servers in a data center. The domain is pretty broad, and the terminology can get quite confusing quickly. This article is my layman’s attempt to sort the basic things out with the minimum words and maximum drawings. The primary focus will be on the Data link layer (OSI L2) of wired networks where the Ethernet is the king nowadays. But I’ll slightly touch upon its neighboring layers too.