A CDN (Content Delivery Network) is a system of distributed servers that improves web content delivery speed, reliability, and security. By directing user requests to the nearest server, CDNs reduce latency and load on the origin server. They're widely used by high-traffic websites and media streaming services to deliver content efficiently to a global audience, enhancing user experience and providing protection against DDoS attacks and traffic spikes.

ESG stands for Environmental, Social, and Governance, referring to the three key factors used to measure a company's sustainability and ethical impact. Investors increasingly use ESG criteria to assess potential investments, aiming to support businesses that are environmentally responsible, socially conscious, and adhere to ethical governance practices. ESG investing aims to promote long-term value creation while addressing global challenges like climate change and social inequality.

Carbon credits are tradable certificates that represent the reduction or removal of one metric ton of carbon dioxide equivalent (CO2e) from the atmosphere. They are used in cap-and-trade systems, where companies or countries have emissions limits and can buy or sell credits to meet these targets. Carbon credits incentivize reducing greenhouse gas emissions and investing in clean technologies, while allowing flexibility in meeting environmental goals.

Scope 3 emissions refer to indirect greenhouse gas emissions occurring throughout a company's value chain, beyond its direct control. These emissions include activities like raw material extraction, product transportation, employee commuting, and waste disposal. Unlike Scope 1 (direct) and Scope 2 (indirect energy-related) emissions, Scope 3 emissions are not owned or controlled by the company but can significantly impact its overall carbon footprint, making them a key target for sustainability initiatives.

Greenhouse gas (GHG) emissions refer to the release of gases that trap heat in the Earth's atmosphere, contributing to global warming and climate change. Major GHGs include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Emissions result from various human activities such as burning fossil fuels, deforestation, and industrial processes. Reducing GHG emissions is crucial for mitigating climate change and its harmful consequences.

The Web produce CO2 emissions because the data centers and servers that host them consume electricity, often generated from fossil fuels. Additionally, user devices and networks accessing websites require energy, which also contributes to emissions. Data transmission, storage, and processing all contribute to a website's carbon footprint. By optimizing web content and using energy-efficient technologies, web services can reduce their associated CO2 emissions and environmental impact.