What is the definition of touching? Does it mean that the skin of a person must touch the source of Tumah, or even if he wears a glove and touches the source of Tumah he will become Tamei?

ב"ה Shalom The issue of touching something Tamei – comes under the category of "Tum'at Maga", a state of Tumah, set off by touching. This is discussed in the Torah. (ויקרא ה:ב) and the Mishna . (כלים א:א, זבים ה:ו). The Rambam (הלכות טומאת מת א:ג) gives us a more defined and focused explanation by expressing clearly that "Tum'at Maga" is transferred when a person's flesh is touched. Elsewhere the Rambaצ, further explains that even if there is a separation of paper tuma'at Maga does is not transferred . (הלכות מטמאי משכב ומושב פרק ט הלכה ג הלכות פרה אדומה פרק יד הלכה ז,) . The Rambam's ruling is also mentioned in the Mishna.( (משנה, פרה י, ו, זבים ה, ה.) All the best