Small talk is meaninglesss conversation in terms of content, but is often seen as socially important in certain situations, or context. In many English-speaking countries, it can be viewed as rude or unfriendly not to participate in it. Non-personal comments about non-controversial subjects are usually considered as appropriate for this type of conversation.
Discussing the weather with people who you don't really know is an example of small talk that many of us are very familiar with on a daily basis. We may chat about the weather with the cashier at the supermarket or with the attendant at the gas station. Making conversation like this may also be related to the situation such as waiting in line. People in the line may comment to others about how slow it is in the post office or bank that day, for instance. People also chat with people we may see every day but don't really know, such as those they share the elevator with at work.
Small talk is common at parties when guests may know the host but not each other. It is considered rude not to mingle and speak with other guests at social functions, so talking about inconsequential subject can break the ice and get guests chatting. Compliments are often used to accomplish this, such as one woman at party complimenting another on her dress. Guests at the buffet table may talk about the types of food offered as they place items onto their plates.
Some people like small talk because they find silence uncomfortable and/or they enjoy communicating verbally. Others enjoy meeting new people and use it to start conversations. Some people don't like these kinds of conversations at all, and often dread going to parties at least partly because of it.
When making small talk, especially with strangers or those you don't know very well, it's important to observe certain socially acceptable conventions. First, all subjects should be general and not personal or about controversial topics. Second, while compliments are acceptable, they shouldn't refer to the person's body or sound like a pick-up line.