Learn SQL, PHP-PDO, JavaScript and Bootstrap for web apps

Python is a general-purpose programming language that became the standard interface for driving numerical and machine-learning code written in other languages.

Git is a distributed version control system that records the history of a set of files as a graph of snapshots, lets many people work on branches of that history at once, and merges their work back together.

HTTP is the request-and-response protocol of the web: a client sends a method, a path and headers, a server answers with a status code, headers and a body, and each exchange stands alone unless the two sides agree to carry state in a header.

A domain name is an address in the internet's public namespace that you rent through a registrar for a yearly fee, and it remains yours only while the registrar account holding it stays paid up and under your own control.

Caching keeps the result of expensive work, such as a rendered page or a database query, and serves that stored copy until it expires, making it the largest single source of speed on any busy website.

Uptime is the proportion of time a service answers requests, quoted in nines, and a service level agreement is the contract clause setting out how that proportion is counted and what the provider owes when it falls short.