The committee members may gather information (receive evidence) about an issue in different ways.
When a committee starts investigating an issue, they may ask people to write to them, setting out what they think about a particular issue. This is called a 'call for evidence'. Anyone can respond to a call for evidence, in writing, through videos or in an audio form (giving written and digital information to a committee).
A committee may also ask people to come to one of its meetings, and answer
questions about the issue they are investigating. This will be done at a committee meeting and is called giving oral evidence.
A committee may also gather other kinds of evidence. For example, it could produce a survey or questionnaire to gather people views, or visit particular projects related the issue they are investigating.