Un billete de ida y vuelta.

Because billete is a masculine noun in Spanish, so it takes the masculine indefinite article un.

• un billete = a ticket
• una entrada = a ticket/admission ticket, but entrada is feminine

You usually have to learn the gender of each noun as part of the word.

In this sentence, billete means a ticket, especially for transport such as trains, buses, or planes.

In Spain, billete is the normal word for a travel ticket. In some Latin American countries, you may also hear boleto or other regional words.

Also note that billete can mean banknote in other contexts, so the exact meaning depends on the situation.

The phrase billete de ida y vuelta literally works like ticket of going and returning. In Spanish, de is often used to link a noun with its type or purpose.

Compare:

• billete de tren = train ticket
• billete de avión = plane ticket
• billete de ida y vuelta = return ticket / round-trip ticket

So de is a very natural connector here.

Ida means the outward journey or going, and vuelta means the return.

Together, ida y vuelta is a fixed expression meaning:

• return
• round trip
• there and back

So un billete de ida y vuelta is a ticket that covers both directions.

Because the expression is treated as a fixed singular idea: one journey consisting of two parts, the outward trip and the return.

So Spanish normally says:

• billete de ida y vuelta

not

• billete de idas y vueltas

The plural version would sound unnatural in this context.

Yes, but it means something different.

• billete de ida y vuelta = return ticket / round-trip ticket
• billete de ida = one-way ticket for the outward journey
• billete de vuelta = ticket for the return journey only

So de vuelta does not mean the whole round trip by itself.

Not really. Grammatically, it is a noun phrase, not a complete sentence with a verb.

It is the kind of phrase you would use in real situations like:

• at a ticket desk
• on a website
• in response to a question

For example:

• ¿Qué desea?
  Un billete de ida y vuelta.

That is perfectly natural in conversation even though it is not a full sentence on its own.

In standard Spain Spanish, billete is pronounced approximately bee-YE-teh.

A few useful points:

• ll is usually pronounced like y in much of Spain today
• the e vowels are short and clear, not like the English name ee
• the stress is on the second syllable: bi-LLE-te

So:

• billete → bee-YE-teh
• ida → EE-da
• vuelta → roughly BWEHL-ta

Uno changes to un before a masculine singular noun.

So:

• un billete
• un tren
• un café

But if the number stands alone, you use uno:

• ¿Cuántos quieres? Uno.

So here, because it comes directly before billete, the correct form is un.

In Spain, un billete de ida y vuelta is much more standard and natural for transport.

You may hear ticket in some specific contexts, especially for receipts, parking machines, or informal borrowed usage, but for trains, buses, and similar travel, billete is the safer and more natural choice.

No. It can be used more broadly to express the idea of going and coming back.

For example:

• un viaje de ida y vuelta = a round trip
• un vuelo de ida y vuelta = a return flight
• un trayecto de ida y vuelta = an outward-and-return journey

So it is a general travel expression, not limited to tickets.