Difference in meaning
 

What is the difference in meaning between "A Lorena le gusta mirar películas" and "Lorena gusta mirar películas" ? I don't understand the meaning that the 'A' and 'le' is bringing to the sentence

For an English speaker, 'gustar' is an unusual verb upon first encounter.
The first sentence in your post correctly makes use of the verb 'gustar'.

Your learning material may have said that it's the equivalent of the English verb 'like', which it is, but the sentence structure reveals that it isn't. English speakers have to learn a new structure to properly use 'gustar'. Many a thread here talks about that structure.

In English, Lorena is the subject (the person who likes something). The thing liked by the subject is the direct object (which can be a noun clause, like 'watching movies', or a noun like 'apple').

In Spanish, things are arranged differently when the verb of the sentence is 'gustar'.
The thing liked (the direct object in English) is the subject of the Spanish sentence. (The subject can precede or follow the verb in Spanish.)
The person who likes something (the subject in English) is the indirect object in Spanish.
(No direct object appears in the Spanish structure.)

'A Lorena' is the indirect object. 'Le' is a redundant indirect object pronoun that means 'to her'. It is common to hear both the indirect object and the indirect object pronoun used together, but it isn't necessary to use both. However, the indirect object pronoun MUST be used if the indirect object is omitted (like when it is understood).

An indirect object is ALWAYS introduced with the preposition 'a'.

Finally, 'ver películas', instead of 'mirar películas', would be a better choice of wording here.


All of the following can be translated into English as 'Lorena likes watching movies'.
A Lorena le gusta ver películas.
Le gusta a Lorena ver películas.
Le gusta ver películas a Lorena.
Ver películas le gusta a Lorena.
A Lorena ver películas le gusta.

If Lorena has already been established, the following mean 'She likes watching movies'.
Le gusta ver películas.
Ver películas le gusta.

As Rusty says, using a redundant object pronoun alongside an explicit object is common, but it isn't always necessary.

In my advanced Spanish language class at university a long time ago, I was taught that there is a difference in how common it is to use a redundant object pronoun together with an explicit object, depending on whether the explicit object occurs *before* its verb or *after* its verb.

When an object occurs *before* its verb, usually its corresponding object pronoun is included.

When an object occurs *after* its verb, it's possible but *not* required to also include its corresponding object pronoun. In this case, including indirect object pronouns is more common than including direct object pronouns.