Chrome vs Safari
Chrome and Safari are web browsers. They are supported by Google and Apple, respectively. Their layout engine, the part responsible for the look and feel of web pages as you view them, is WebKit. WebKit is an open source project built on code from the KDE community's "KHTML" and new code from Apple.
Chrome is a proprietary build by Google of the open source Chromium project - so Chromium and Chrome are nearly identical. Apple creates WebKit nightly builds as a version of Safari for the open source WebKit project.
 Crash Recovery
Chrome uses a separate process for each browser tab. Safari uses one process for each browser window. When a page crashes in Chrome, typically only the individual tab it was in will crash. When a page crashes in Safari, usually the Safari browser window crashes.
Occasionally, all tabs in one window in Chrome will crash. Occasionally, when one window crashes in Safari, the browser must be shut down along with all browser windows.
Many of the crashes experienced in each browser are caused by problems in the WebKit engine. While the effect of a crash is not the same in each browser, crashes happen equally often in Safari and Chrome (approximately).
In practical terms, there is usually no noticeable difference in speed - a big part of each browser's performance is determined by the WebKit layout engine.
 Operating System
Chrome is available for Linux, Windows, and Mac OS X. Safari is was available for OS X and Windows, but stopped supporting Windows after Safari 5 due to lack of consumer adoption. Also, the Open-Source version, Chromium, is available on Linux, FreeBSD, Solaris, and pretty much every operating system with a c compiler similar to GCC.
Chrome was designed to "wrap" around programs that run inside a web browser (be the "chrome" around web applications). It takes up a minimal amount of screen space for its own interface.
Safari uses a more traditional browser interface elements, but in the end takes up exactly the same space as Chrome with the bookmarks bar enabled on each. Safari now combines the address and search bars, like Chrome.
Safari downloads go in a drop down menu in the toolbar, whereas Chrome downloads show up at the bottom of the browser window.
A reading list save for later feature came to Safari with iCloud that syncs to iOS devices. Also, password management is in the current beta for OS X 10.9. In Chrome you can now sign in to sync tabs with iOS and Android versions of Chrome. Both have selections of free extensions available in a managed store. Safari has allowed you to install extensions from 3rd party sites since before Apple even officially supported extensions, but Chrome by default cannot.