What does "Beta" mean, in relation to the internet/website/programs/apps?

From Wikipedia:

“A beta version is the first version released outside the organization or community that develops the software, for the purpose of evaluation or real-world black/grey-box testing. The process of delivering a beta version to the users is called beta release. Beta level software generally includes all features, but may also include known issues and bugs of a less serious variety.

The users of a beta version are called beta testers. They are usually customers or prospective customers of the organization that develops the software. They receive the software for free or for a reduced price, but act as free testers.

Beta versions test the supportability of the product, the go-to-market messaging (while recruiting Beta customers), the manufacturability of the product, and the overall channel flow or channel reach.

Beta version software is likely to be useful for internal demonstrations and previews to select customers, but unstable and not yet ready for release. Some developers refer to this stage as a preview, a prototype, a technical preview (TP) or as an early access. As the second major stage in the release lifecycle, following the alpha stage, it is named after the Greek letter beta, the second letter in the Greek alphabet.”

Alpha comes before beta, obviously, and is generally internal only testing.

Beta software is still a testing phase with known issues and incomplete features. Beta testing can be either public or private, but generally expands outside the organization.
Generally, these apps will be denoted by a . (dot) then a version number. Such as .6801 .With the first non-beta release being 1.0.

Beyond beta, some developers will either have final betas or release candidates. You may see an RC1 or RC2.

A here’s a fun marketing factoid…

A dot-oh (like 1.0, 2.0, 3.0) is typically regarded by the general populace as only slightly better than beta. So often times, people wanting an even more stable release will wait for the dot-one (like 1.1, 2.1, 3.1) or later before making a significant upgrade/purchase.

Marketing divisions at companies know this. So, in some cases, they’ll direct that a first release will come out as a dot-one, not a dot-oh (like a major upgrade release going from 3.5 straight to 4.1).

My only point in mentioning this is that you should acquaint yourself with the release history of any product which for you represents a significant investment in time, money, or effort. And that some companies have better beta releases than other companies dot-ones.

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For you Mac lovers, Mac OS X uses a three-tier numbering convention. Leopard, the current release was first released as 10.5 (implied ”.0” on the end). Subsequent updates to Leopard are 10.5.1 and 10.5.2 (which is current). Tiger, the previous major OS X release, is currently supported at version 10.4.11.

that means: if you decide to install a BETA program! you must take some unknown risks that come from the bugs or any incomplete features!

It really depends on the application/website/whatever, just like version numbering.

Some websites like to slap “beta” on it so they can keep experimenting with features and when people experience bugs just point to the “beta” on the logo.

On the other hand, some applications like Firefox or Ubuntu release a version as “beta” when they really want it to be tested and the test results reported. The Firefox beta releases especially are about as stable as most other applications, which definitely isn’t the case for most “beta” applications.

Like Vincentt said, it really varies from application to application. I don’t really mind the beta label so long as it doesn’t affect the user experience too much. For instance, Google is notorious for keeping software in beta for years—which may be semantically flawed, but they don’t use it as an excuse for having bugs in their software, so it doesn’t really affect my experience. Some people feel differently.

Software that uses a public beta as an excuse to have bugs while acquiring a large user base kind of annoys me. But not too much—the joke’s really on them because if their work is crappy, I might not come back, even once they’re out of beta.