Nothing ticks me off like being invited to the latter and running full bore into the former. What is the difference between the two, you ask? And why is it important? Well, let us step back a moment and take a look at this conceptually singular phenomenon that has, over time, evolved into a duality.
A wine event is generally put on by a local wine purveyor and can run the gamut from a group of regulars who have been called together, to a wine dinner, to a mega-event taking up many city blocks. The common characteristics are: it is generally pre-scheduled and publicized; the wines on offer are pre-announced; a guest-of-honor is generally associated with the event and is pre-announced; and, there may or may not be a "cover charge."
The wine retailer's objective in putting the event together is to drive increased revenue in both the short and long term. In the short term, there is a bump in revenue from the participation fee as well as the sales coming out of the event. If the product is on hand, the revenue bump is immediate. If the product is shipped in post the event, the revenue is further down the road (assuming that the retailer does not collect pre-arrival).
The objectives of the attendees differ depending on their level of sophistication but it is bound together under a common rubric: education. An equilibrium is reached when the purveyor provides enough information to allow the attendee to make an informed purchase decision. Further, if the attendee feels that he/she is consistently informed at this particular facility, he/she will keep coming back, with positive, long-term implications for the enterprise.
Now back to wine pouring versus wine tasting.
If your wine shop owner invites you to an event where there are four wines and these wines are poured into your glass by a salesperson who says "Parker gave this a 92" or "great wine" or "check out the nose on this baby," you are at a wine pouring. Note that the determining factor as to whether or not it is a wine pouring is not the size/scope of the event, but the activities within and the substance derived therefrom by the attendees. As a matter of fact, if you are at an event, and the winemaker is pouring the wine into your glass and making these non-value-laden statements, you are still at a wine pouring.
The hallmark of a wine tasting is an event that delivers quality (or not) wine and some relevant knowledge about the subject wine. Wine dinners are a classic example of a "true" wine tasting: The wine is poured by a team; each patron has the same wine in his/her glass simultaneously; someone with a more-than-cursory knowledge of the wine expounds on its qualities; and it is consumed in total before we move on to the next wine. In addition, a quality wine tasting has a limited number of attendees, has a clear, written description of the subject wines, has material available which the attendee can use to make notes about the wines and the event, and has an easy-to-understand order form.
The wine beginner should always opt for a wine tasting before a wine pouring. When I leave a wine tasting I hope to know: The wine-making philosophy of the winemaker; the region where the grapes were grown; any growing difficulties associated with the vintage; the wine-making process; what sets this wine apart from other wines; and the critics' perspectives. For someone who is familiar with the wine maker's style and previous vintages, a wine pouring fits the bill in that they can be exposed to the latest edition of the wine(s) without a lot of diversion.