pleasure
The Italian word 'piacere' can be used as both a noun and a verb. As a noun, it translates to 'pleasure' or 'enjoyment'. For example, 'Mi dà piacere vederti' means 'It gives me pleasure to see you'. As a verb, 'piacere' means 'to please' or 'to like'. In this context, the subject is the thing or person that is liked, and the object is the person who experiences the pleasure. For example, 'Mi piace la pizza' means 'I like pizza'.
I'm pleased to meet you
This is a common phrase used when meeting someone for the first time. 'Mi fa piacere' translates literally as 'it makes me pleasure', but in context, it's equivalent to 'I'm pleased'. 'Conoscerti' is the infinitive form of the verb 'to know'.
Maria likes pizza
This phrase uses 'piacere' in the context of liking something. Here, it's used to demonstrate that Maria enjoys pizza. In Italian, the thing that someone likes (in this case, 'la pizza') typically comes before 'piacere'.
Nice to see you
This phrase is used when you are glad to see someone. 'Piacere' is used here in a way that translates to 'pleasure', so the literal translation of the sentence would be 'Pleasure of seeing you'. However, in English the more natural way to say this would be 'Nice to see you'.