die Last
load
A physical weight that has to be carried or transported.
Der Wanderer trug eine schwere Last auf seinem Rücken.
The hiker carried a heavy load on his back.

burden / load
Loading your saved state.
load
A physical weight that has to be carried or transported.
Der Wanderer trug eine schwere Last auf seinem Rücken.
The hiker carried a heavy load on his back.

Careful: 'die Last' means 'burden' or 'load'. It is a common mistake to confuse it with the English word 'last' (German: 'letzt-').
Die schwere Kiste war eine große Last.
The heavy box was a great burden.
The literal meaning (weight) is often recognizable from verbs like 'tragen' (to carry) or 'heben' (to lift). The figurative meaning (burden/strain) is usually used with abstract nouns like 'Verantwortung' (responsibility), 'Sorgen' (worries), or 'Kosten' (costs).
Der Kran hob die schwere Last vom Schiff.
The crane lifted the heavy load from the ship.
In the figurative sense, 'Last' (burden) is often used metaphorically. Typical phrases are 'eine Last von den Schultern nehmen' (to take a burden off someone's shoulders), 'eine seelische Last sein' (to be an emotional burden), or 'eine Last mit sich herumtragen' (to carry a burden around with oneself).
Nach dem Gespräch fühlte er sich, als wäre ihm eine Last von den Schultern gefallen.
After the conversation, he felt as if a burden had been lifted from his shoulders.
The fixed expression 'jemandem zur Last fallen' (to be a burden to someone) always uses the dative. The person who becomes the burden is the subject of the sentence.
Im Alter möchte sie ihren Kindern nicht zur Last fallen.
In old age, she does not want to be a burden to her children.
responsibility
'Verantwortung' and 'Last' can both have to do with a difficult task. 'Verantwortung' mainly means the duty to take care of something and to answer for the consequences. This can be important and serious, but it does not have to sound negative. 'Last', on the other hand, emphasizes that something weighs heavily on a person, for example as a worry or pressure. Learners may confuse the words when a responsibility is very demanding. Then it can also be felt as a Last. In practice: 'Verantwortung' fits when the focus is on duty and responsibility; 'Last' fits when you want to emphasize heaviness or pressure.

Nach dem Streit wurde die Sorge um die Familie für ihn zu einer schweren Last.
After the argument, worrying about the family became a heavy burden for him.
Sie trägt die Verantwortung für das neue Projekt im Büro.
She is responsible for the new project at the office.