管弦乐队是orchestra的翻译，交响乐队是symphony orchestra的翻译，爱乐乐队是philharmonic orchestra的翻译。这三者都是一回事，都是指大型管弦乐队，区别于小型管弦乐队——室内乐队（chamber orchestra）。你别看室内乐队名字里也有orchestra，但如果单独说orchestra，通常只是指大型管弦乐队而不包括室内乐队。

如果一个城市有几个不同的乐团，这些不同的名称可以用来区别。比如“上海交响乐团”、“上海爱乐乐团”和“上海管弦乐团”。

下面转贴一段viki的条目：

Orchestra
From Wikipedia, the free encyclopedia.

Orchestra at City Hall (Edmonton).An orchestra is a musical ensemble used most often in classical music. A small orchestra is called a chamber orchestra.

A full size orchestra may sometimes be called a "symphony orchestra" or "philharmonic orchestra"; these prefixes do not indicate any difference either to the instrumental content or role of the orchestra, but can be useful to distinguish different orchestras based in the same city (for instance, the London Symphony Orchestra and the London Philharmonic Orchestra). A symphony orchestra will usually have over eighty musicians on its staff, in some cases over a hundred, but the number of musicians used in a performance varies according to the work being played. A leading chamber orchestra might be forty or fifty strong; some are much smaller than that. Orchestras sometimes use freelance musicians to enable them to perform works which require instrumentalists which they do not have on staff; not all orchestras employ a harpist for example.