Это салон, в котором мне быстро высушили чёлку феном.

Both can mean where in English, but they work a little differently in Russian.

• где = where
• в котором = literally in which

So:

• Это салон, где... = This is the salon where...
• Это салон, в котором... = This is the salon in which...

In this sentence, в котором sounds a bit more explicit and slightly more formal/bookish than где. In everyday speech, many people would also say:

• Это салон, где мне быстро высушили чёлку феном.

Both are natural.

Because the pronoun который has to match both:

1. the noun it refers to, and
2. the case required by the preposition.

It refers back to салон, which is:

• masculine
• singular

And because the phrase is в ... meaning in ..., Russian uses the prepositional case here.

So:

• base form: который
• masculine singular prepositional: котором

That gives:

• в котором = in which

Мне is the dative case of я.

• я = I
• мне = to me / for me

Russian often uses the dative when something is done to someone or for someone, especially in service situations or with body parts/hair/clothing.

So:

• мне быстро высушили чёлку
  literally: they quickly dried the fringe to/for me

A more natural English rendering is:

• they quickly dried my bangs
• they quickly blow-dried my fringe for me

Because Russian very often omits possessive words like my, his, her when the ownership is obvious from context.

Here, мне already tells us whose fringe it is. So чёлку is understood as my fringe/bangs.

This is especially common with:

• body parts
• hair
• clothing
• personal belongings in obvious situations

So Russian prefers the more natural, less repetitive:

• мне высушили чёлку

rather than:

• мне высушили мою чёлку

The version with мою is possible, but it would usually sound more emphatic than necessary.

Because чёлку is the direct object of высушили.

The dictionary form is:

• чёлка = fringe / bangs

It is a feminine noun, so its singular forms are:

• nominative: чёлка
• accusative: чёлку

Since the action is being done to the fringe, Russian uses the accusative case:

• высушили что? → чёлку

Because Russian often uses the instrumental case to show the tool or means used to do something.

• фен = hairdryer
• феном = with a hairdryer

So:

• высушили феном = dried with a hairdryer

This is a very common pattern:

• писать ручкой = write with a pen
• резать ножом = cut with a knife
• открыть ключом = open with a key

This is a question of aspect.

• сушить / сушили = imperfective
  focuses on the process: were drying / dried
• высушить / высушили = perfective
  focuses on the completed result: dried completely / finished drying

In this sentence, the meaning is that the action was completed: the fringe ended up dry. That is why высушили is used.

So the sentence is about a finished service, not just the process.

The verb высушили is past tense plural. Literally, it means they dried.

But Russian often uses a plural verb with no stated subject when the people are unknown, unimportant, or obvious from context.

Here it means something like:

• they dried my fringe
• someone at the salon dried my fringe
• the staff dried my fringe

This is very common in Russian and often sounds more natural than naming the person directly.

Because в котором мне быстро высушили чёлку феном is a relative clause describing салон.

Russian normally separates this kind of clause with a comma:

• Это салон, в котором...

It works like English:

• This is the salon where...
• This is the salon in which...

Russian punctuation is usually stricter than English here, so the comma is required.

Not by the word alone.

Салон can mean several things depending on context, such as:

• salon
• beauty salon
• hair salon
• showroom
• studio-like commercial place

But in this sentence, because we have:

• чёлку = fringe/bangs
• феном = with a hairdryer

the natural interpretation is:

• a hair salon
• or more broadly, a beauty salon/hair salon

Это is commonly used in Russian to identify or point something out:

• Это дом. = This is a house.
• Это мой брат. = This is my brother.
• Это салон... = This is the salon...

So Это салон, в котором... means:

• This is the salon where...
• This is the salon in which...

It is a very common sentence pattern for introducing or identifying something.

Yes. Russian word order is flexible, although not completely free.

The sentence as given is natural:

• Это салон, в котором мне быстро высушили чёлку феном.

But other versions are also possible, for example:

• Это салон, в котором мне чёлку быстро высушили феном.
• Это салон, в котором чёлку мне быстро высушили феном.

These versions may sound slightly different in emphasis, but the core meaning stays the same.

The original order is a good neutral choice:

• place first
• then recipient (мне)
• then adverb (быстро)
• then verb
• then object
• then instrument

Because the standard spelling of the word is:

• чёлка

The letter ё shows the sound yo.

In many printed texts, Russian writers replace ё with е, so you may also see:

• челка

But the correct pronunciation is still with ё:

• чёлка → roughly chyolka

For learners, it is helpful to remember that the actual word is чёлка, even if many texts write челка.