Time dilation is a phenomenon predicted by the theory of relativity, specifically the theory of special relativity. It refers to the difference in the passage of time between two observers who are in relative motion or experiencing different gravitational fields.
According to special relativity, as an object approaches speeds close to the speed of light, time appears to pass more slowly for that object relative to a stationary observer. This means that the moving object's internal processes, such as its clocks or aging, would be observed to slow down from the perspective of the stationary observer. This effect is known as time dilation.
Similarly, time dilation occurs when there is a difference in gravitational potential between two observers. In a stronger gravitational field, time appears to pass more slowly compared to a weaker gravitational field.
Now, regarding your second question, according to our current understanding of physics, it is not possible to travel faster than the speed of light. The theory of special relativity states that as an object with mass accelerates towards the speed of light, its energy and momentum increase significantly, requiring an infinite amount of energy to actually reach or exceed the speed of light. This is why it is commonly believed that nothing with mass can travel faster than light.
Since time dilation is a consequence of traveling at speeds close to the speed of light, it cannot be avoided by exceeding the speed of light because that is not possible within our current understanding of physics. Time dilation is an inherent feature of the universe as described by the theory of relativity, and it manifests when objects move at significant fractions of the speed of light or experience different gravitational potentials.