Yes, might be the immediate answer, but close is relative. You want to be close enough to the wildlife to get great photographs, but you shouldn’t be too close and get the animal agitated. Most African safaris offer bush walks as part of lodge activities and they are a great opportunity to experience the bush from the same level as the animals. However, listen to the instructions and stay close to your guide. Also with game drive vehicles you can get too close to for example elephants and you don’t want to make an elephant angry. Respect the animals, don’t get in their path and watch out for possible signs of their discomfort.
For more advice for the right behavior around animals read Alan Murphy’s post right here.